Discourse Open Source Discussion Platform
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Products by Discourse Sorted by Most Security Vulnerabilities since 2018
By the Year
In 2026 there have been 134 vulnerabilities in Discourse with an average score of 5.5 out of ten. Last year, in 2025 Discourse had 25 security vulnerabilities published. That is, 109 more vulnerabilities have already been reported in 2026 as compared to last year. However, the average CVE base score of the vulnerabilities in 2026 is greater by 1.44.
| Year | Vulnerabilities | Average Score |
|---|---|---|
| 2026 | 134 | 5.47 |
| 2025 | 25 | 4.03 |
| 2024 | 34 | 5.68 |
| 2023 | 64 | 5.67 |
| 2022 | 38 | 5.70 |
| 2021 | 19 | 5.96 |
| 2020 | 0 | 0.00 |
| 2019 | 3 | 6.37 |
It may take a day or so for new Discourse vulnerabilities to show up in the stats or in the list of recent security vulnerabilities. Additionally vulnerabilities may be tagged under a different product or component name.
Recent Discourse Security Vulnerabilities
| CVE | Date | Vulnerability | Products |
|---|---|---|---|
| CVE-2026-91119 | Sep 24, 2026 |
Discourse XSS via Unescaped action_code_who URL Before 2026.1.8/6.3/7.2/8.0Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, the topic small-action and nested-activity-log components interpolated the free-form action_code_who value into mention-link href attributes without URL encoding. A quote-bearing display name could terminate the intended URL attribute and inject attacker-controlled elements into the trusted rendered markup. Although the visible mention text was escaped, the unencoded path component allowed stored HTML injection when another user viewed the affected topic action or activity log. This issue is fixed in versions 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0. |
Discourse
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| CVE-2026-91121 | Sep 24, 2026 |
Discourse <2026.1.8/6.3/7.2/8.0: Trusted HTML Injection via Chat FilenamesDiscourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, attacker-controlled upload filenames used in chat message excerpts were rendered as unescaped HTML. A user able to upload a file and send chat content could place markup in a filename that was then interpreted by chat channel lists, chat summary emails, pinned message bars, reply previews, thread previews, and other excerpt renderers. The issue allowed trusted-HTML injection that altered rendered excerpt content, but JavaScript execution was not demonstrated with default Content Security Policy settings. The advisory states that no confidentiality, integrity, or availability impact was identified, while its structured scoring metadata separately assigns low integrity impact. Sites that disable or relax the default CSP have increased exposure. This issue is fixed in versions 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0. |
Discourse
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| CVE-2026-91120 | Sep 24, 2026 |
Discourse 2026 Lazy Video Title XSS in Email/Chat (pre2026.1.8)Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, provider-controlled video titles in lazy video embeds could be reparsed as HTML when Discourse generated notification emails or chat summaries. A user with standard posting privileges could create a post for an enabled YouTube, Vimeo, or TikTok provider whose title contained markup, and the email and chat-summary rendering path would place that markup into the output instead of treating it solely as text. Recipients using HTML-capable email clients could see injected content, potentially including event handlers, but the issue did not directly expose a Discourse browser session or affect the forum page itself. Lazy video embeds must be enabled, which is the default configuration. This issue is fixed in versions 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0. |
Discourse
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| CVE-2026-91132 | Sep 24, 2026 |
Discourse Wildcard Iframe Allowlist Bypass (2026.1.8)Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, sites using wildcard patterns in the allowed_iframes setting could accept a crafted iframe URL whose allowlisted suffix appeared after a URL authority separator. The wildcard origin check matched the allowed domain text, while browser URL parsing selected a different attacker-controlled origin. A user with posting privileges could exploit the flaw through a post or a Onebox oEmbed response and cause an attacker-controlled iframe to be rendered independently of the allowlisted domain. Successful exploitation requires a site-configured wildcard iframe pattern and the ability to create a post or trigger an oEmbed request for an attacker-controlled URL. This issue is fixed in versions 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0. |
Discourse
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| CVE-2026-91122 | Sep 24, 2026 |
Discourse Video Placeholder XSS via Injected Event Handler (pre-2026.1.8)Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, the video placeholder component allowed crafted HTML to cause an attribute breakout and inject an attacker-controlled event handler. An authenticated user with default trust-level posting privileges could store the crafted placeholder in a post. When another user opened the post and clicked the video play overlay, the handler could execute arbitrary JavaScript in the viewer's session. Default Content Security Policy settings block inline event handlers, but instances with CSP disabled or relaxed could allow the script to read page content and make authenticated requests as the viewer. This issue is fixed in versions 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0. |
Discourse
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| CVE-2026-91123 | Sep 24, 2026 |
Discourse iframe src traversal guard bypass (2026.8.0)Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, the iframe src traversal guard did not treat literal backslashes as path separators after decoded dot segments. A crafted source could therefore pass an allowed_iframes subpath check while browser URL normalization moved the iframe outside the intended allowed path. The resulting iframe could load content from a location that the administrator did not allow. This issue is fixed in versions 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0. |
Discourse
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| CVE-2026-91133 | Sep 24, 2026 |
Discourse SQL LIKE Wildcard Disclosure 2026.8.0Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, authenticated users could supply unescaped SQL LIKE metacharacters to upload-resolution patterns, causing wildcard input to select unrelated upload records instead of matching a literal identifier. The affected upload metadata, URL-lookup, and cooked-video-placeholder paths could resolve uploads the user was not authorized to access. This allowed disclosure of restricted metadata, including original filenames and secure-upload paths, without modifying the upload records. This issue is fixed in versions 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0. |
Discourse
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| CVE-2026-91134 | Sep 24, 2026 |
Discourse: Stored XSS via iframe encoded userinfo, fixed v 2026.1.8/6.3/7.2/8.0Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, the Discourse post sanitizer allowed a stored cross-origin iframe to bypass the allowed_iframes prefix policy when the iframe src contained encoded userinfo. The sanitizer validated a decoded form differently from the stored iframe src, allowing the browser to interpret an attacker-controlled host while the allowlist check accepted the encoded URL as an allowed prefix. An authenticated user with posting privileges could persist the iframe in a post and cause attacker-controlled cross-origin content to be rendered. This issue is fixed in versions 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0. |
Discourse
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| CVE-2026-84302 | Sep 24, 2026 |
Discourse AI Reviewable Disclosure in Private Messages (v<2026.1.6)Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, Discourse AI reviewables associated with private messages could appear in the moderator review queue of a moderator who was not a participant in the message. Reviewable visibility filtering did not restrict private-message reviewables to the audience permitted to access the underlying private-message topic, allowing the moderator to read otherwise confidential content. Depending on the available reviewable action, the moderator could also modify the private message by closing its topic or deleting a post. Exploitation requires an authenticated moderator account and a pre-existing Discourse AI reviewable associated with a private message. This issue is fixed in versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0. |
Discourse
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| CVE-2026-59830 | Sep 21, 2026 |
CrossSite Scripting in Discourse Post Action (<2026.7.0)Discourse is an open-source discussion platform. Prior to 2026.7.0, the post action component failed to escape user-controlled display names before interpolating them into an HTML string passed to trustHTML. A user who could choose a crafted display name could persist markup in post action descriptions. Viewing the affected user activity streams could execute attacker-controlled script in another user's browser. This issue is fixed in version 2026.7.0. |
Discourse
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| CVE-2026-53960 | Aug 17, 2026 |
Discourse <=2026.7.0 QAPage JSON-LD leaks hidden firstpostDiscourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, hidden or otherwise unviewable first-post content was leaked as an excerpt in the publicly-served Q&A (QAPage) JSON-LD structured data, exposing it to any unauthenticated visitor and to search-engine crawlers. This issue is fixed in versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0. |
Discourse
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| CVE-2026-55704 | Aug 17, 2026 |
Discourse Shared-Draft I.D. via Group Endpoints <2026.7.0Discourse is an open-source discussion platform. Prior o 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, users who were allowed to view a groups activity, but were not permitted to see shared drafts, could still receive shared-draft entries through the group posts and group mentions endpoints. This could disclose shared-draft topic titles and post excerpt/content, resulting in an information disclosure of unpublished draft material. This issue is fixed in versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0. |
Discourse
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| CVE-2026-55674 | Aug 17, 2026 |
Discourse 2026.x XSS via color_scheme_id Cookie (before 2026.7.0)Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, an unauthenticated attacker could send a single request with a crafted color_scheme_id (or dark_scheme_id) cookie to inject arbitrary HTML into a Discourse page. Because the cookie value was rendered into a color scheme tag without escaping, the attacker could break out of the attribute and inject a tag that bypassed Discourse's nonce-based Content Security Policy, resulting in arbitrary JavaScript execution in visitors' browsers. This issue is fixed in versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0. |
Discourse
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| CVE-2026-59829 | Aug 17, 2026 |
Discourse 2026.1.5 Review Queue Exposes PM Excerpts to Unauthorized ModsDiscourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.1, on sites with category group moderation enabled, the review queue could include an excerpt (and permalink) of the private message attached to a flag, even when the reviewing category moderator was not a participant in that message. These notify_moderators flag messages are addressed only to moderators and, for core flags, to a category's moderation groups as they existed when the flag was raised, so a category group moderator could read flag-discussion content they were not authorized to see. This affects official plugins that create such messages and core flags raised before a moderator's group was granted moderation of the category. Only the confidentiality of a limited excerpt of these flag-related private messages is affected; no content can be modified or deleted. This issue is fixed in versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.1. |
Discourse
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| CVE-2026-72732 | Aug 10, 2026 |
Discourse v2026.* TemplatesSerializer Tag Leak (CVE-2026-72732)Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, the discourse_templates endpoint exposed hidden tag names because DiscourseTemplates::TemplatesSerializer in plugins/discourse-templates/app/serializers/discourse_templates/templates_serializer.rb did not filter tags through the request Guardian. The serializer did not respect tag group permissions, allowing users to see tags they were not permitted to view. This issue is fixed in versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0. |
Discourse
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| CVE-2026-72731 | Aug 10, 2026 |
SQL Injection via Parameterized Queries in Discourse 2026.1.0-2026.1.6Discourse is an open-source discussion platform. From 2026.1.0-latest until 2026.1.7, 2026.6.2, 2026.7.1, and 2026.8.0-latest.1, anyone able to run a parameterized Data Explorer query, including non-staff members of a group a query is shared with, could craft parameter values that escaped the intended query and executed arbitrary SQL through plugins/discourse-data-explorer/lib/discourse_data_explorer/data_explorer.rb and plugins/discourse-data-explorer/lib/discourse_data_explorer/workflows/sql_action/v1.rb. Recursive parameter interpolation allowed one parameter value to introduce another parameter, and parameter declarations in SQL comments could be used to inject a statement. Queries run in a read-only transaction, so data could not be modified, but any table could be read. This issue is fixed in versions 2026.1.7, 2026.6.2, 2026.7.1, and 2026.8.0-latest.1. |
Discourse
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| CVE-2026-72730 | Aug 10, 2026 |
Discourse XSS in RTE ( 2026.1.5, <2026.5.2, <2026.6.1, <2026.7.0)Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, the Rich Text Editor rendered a chat-transcript username as HTML, allowing stored cross-site scripting. This issue is fixed in versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0. |
Discourse
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| CVE-2026-72729 | Aug 10, 2026 |
Discourse-local-dates XSS via HTML Render before 2026.1.6Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, the discourse-local-dates plugin rendered crafted local-date format data as HTML on sites with a modified or disabled default Content Security Policy. This issue is fixed in versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0. |
Discourse
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| CVE-2026-72728 | Aug 10, 2026 |
Discourse Onebox Allowlist Bypass (<2026.1.7)Discourse is an open-source discussion platform. Prior to 2026.1.7, an authenticated user could submit specially formed URLs that bypassed the Onebox allowlist and embedded malicious content in a site. This issue is fixed in versions 2026.1.7, 2026.6.2, 2026.7.1, and 2026.8.0-latest.1. |
Discourse
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| CVE-2026-72727 | Aug 10, 2026 |
Discourse XSS via Moderation Queue before 2026.1.6, 2026.5.2, 2026.6.1, 2026.7.0Discourse is an open-source discussion platform. Prior to 026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, a low-privileged user could place crafted content in the moderation review queue that executed stored cross-site scripting when a moderator viewed it on a site with a modified or disabled default Content Security Policy. This issue is fixed in versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0. |
Discourse
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| CVE-2026-72726 | Aug 10, 2026 |
Auth Authenticated AI Bot Reply Replay Disclosure in Discourse <2026.1.6Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, an authenticated user could eavesdrop on private AI bot conversations through the AI bot reply stream. The issue is fixed in 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0. |
Discourse
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| CVE-2026-72725 | Aug 10, 2026 |
Discourse XSS in Staff Action Log (before 2026.1.6)Discourse is an open-source discussion platform. Prior to 2026.1.6, the staff action log model rendered unescaped previous and new value fields that could inject stored cross-site scripting into the staff interface. The issue is fixed in 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0. |
Discourse
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| CVE-2026-72724 | Aug 10, 2026 |
Discourse onebox_handler.rb Chat Thread Disclosure before 2026.1.6Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, plugins/chat/lib/chat/onebox_handler.rb resolves Chat::Thread by route thread_id independently of the route channel_id before checking whether the user can preview the selected chat channel. An authenticated user can pair a public channel ID with a private thread ID in a /onebox.json request and obtain private thread message content. This issue is fixed in versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0. |
Discourse
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| CVE-2026-72723 | Aug 10, 2026 |
Discourse <2026.1.6 & 2026.5.2: Tag Exposure via /site.json (Unauth)Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, SiteSerializer.anonymous_default_navigation_menu_tags serializes tags from SiteSetting.default_navigation_menu_tags without applying DiscourseTagging.filter_visible for the anonymous viewer. An unauthenticated user can retrieve restricted tag names and descriptions through /site.json when those tags are limited by inaccessible categories, category tag groups, or tag-group permissions. This issue is fixed in versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0. |
Discourse
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| CVE-2026-72722 | Aug 10, 2026 |
Discourse 2026.x TopicLink Duplicate Lookup Leads to Unauthorized Data ExposureDiscourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, TopicLink.extract_from, TopicLink.ensure_entry_for, and TopicLink.duplicate_lookup do not consistently enforce Guardian.can_see? checks when processing internal links. An authenticated user can submit links to restricted topics, private messages, or hidden posts and receive canonicalized slugs or titles in the composer_messages duplicate_lookup response even though the targets are not visible to that user. This issue is fixed in versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0. |
Discourse
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| CVE-2026-72721 | Aug 10, 2026 |
Discourse Onebox Domain Checker Case-Sensitivity Bypass (v2026.7.0)Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, Onebox::DomainChecker.is_blocked? compares hostnames and SiteSetting.blocked_onebox_domains entries case-sensitively, allowing an attacker to bypass configured Onebox domain restrictions by changing character casing in a redirect target hostname. This issue is fixed in versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0. |
Discourse
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| CVE-2026-72720 | Aug 10, 2026 |
Discourse PrettyText.format_for_email HTML Injection (v 2026.1.7 and older)Discourse is an open-source discussion platform. Prior to 2026.1.7, 2026.6.2, 2026.7.1, and 2026.8.0-latest.1, Discourse has HTML injection in PrettyText.format_for_email because cooked attribute values are reparsed as markup. Crafted Vimeo iframe sources, secure-upload URLs or dimensions, and hashtag data-slug values can cause decoded attribute text to be reinterpreted as HTML. The vulnerable conversion also fails to strictly validate the Vimeo iframe host and path, allowing non-Vimeo allowlisted iframes to be converted. This issue is fixed in versions 2026.1.7, 2026.6.2, 2026.7.1, and 2026.8.0-latest.1. |
Discourse
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| CVE-2026-45780 | Jul 09, 2026 |
Discourse EventSerializer Info Leak Exposes Invitee Data Pre-2026.6Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, EventSerializer could expose invited group names, sample invitees, and attendance statistics to users who could view the topic but were not entitled to view the private event invitee list. This issue is fixed in versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5. |
Discourse
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| CVE-2026-53963 | Jul 09, 2026 |
Discourse XSS via Unescaped SF Name in Admin Dialog 2026.6.0Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, a malicious second factor name on an attacker-controlled account was not escaped in the delete confirmation dialog, allowing stored cross-site scripting when an administrator impersonated that account. This issue is fixed in versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5. |
Discourse
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| CVE-2026-59828 | Jul 09, 2026 |
Discourse post diff leakage before 2026.6.0 (CVE-2026-59828)Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, post revisions that should be hidden from regular users could be leaked through visible diffs on adjacent revisions serialized by PostRevisionSerializer. This issue is fixed in versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5. |
Discourse
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| CVE-2026-44787 | Jul 09, 2026 |
Discourse <2026.6 Signup flow: Whisper group privilege escalationDiscourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, the signup flow could allow newly registered users to set primary_group_id and gain whisper-group privileges without legitimate group membership on sites with whispers_allowed_groups configured. This issue is fixed in versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5. |
Discourse
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| CVE-2026-53962 | Jul 09, 2026 |
Discourse XSS via SVG Sanitization in Upload/Avatar (2026.6.0)Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, insufficient SVG sanitization in upload and user avatar handling could lead to cross-site scripting when a user visited specific URLs that are not normally part of community browsing. This issue is fixed in versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5. |
Discourse
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| CVE-2026-55424 | Jul 09, 2026 |
Discourse X before 2026.6.0 XSS via unescaped featured linkDiscourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, a topic "featured link" was not sufficiently normalized and escaped before being rendered in the topic list, allowing a user who can set a featured link to inject JavaScript when default Content Security Policy protections were modified or disabled. This issue is fixed in versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5. |
Discourse
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| CVE-2026-45788 | Jul 09, 2026 |
Discourse Secure Upload Exposure via pull_hotlinked_images (pre-2026.6.0)Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, secure uploads could be exposed by pull_hotlinked_images when an attacker knew the secured upload URL and the secure_uploads site setting was enabled. This issue is fixed in versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5. |
Discourse
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| CVE-2026-49256 | Jul 09, 2026 |
Discourse <2026.6.0 tag leakage via category endpoints (allowed_tags)Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, restricted tag and tag-group names attached to publicly readable categories as allowed_tags, allowed_tag_groups, or required tag groups could leak to anonymous and unauthorized users through category and group endpoints. This issue is fixed in versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5. |
Discourse
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| CVE-2026-46413 | Jul 09, 2026 |
Discourse ExternalUploadManager S3 PrivEsc pre-2026.6.0Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, regular users could route direct S3 multipart uploads through ExternalUploadManager into the admin backup store. This issue is fixed in versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5. |
Discourse
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| CVE-2026-53961 | Jul 09, 2026 |
Discourse AWS SES Bounce Webhook Bypass <2026.6.0 via unbound SNS TopicArnDiscourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, the AWS SES bounce webhook at POST /webhooks/aws verified that SNS messages were signed by Amazon but did not bind them to trusted TopicArn values, allowing any AWS account holder to publish validly signed forged Bounce notifications that revoke a targeted user email. This issue is fixed in versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5. |
Discourse
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| CVE-2026-55420 | Jul 09, 2026 |
Discourse PDF upload RCE before 2026.6.0/2026.5.1/2026.4.2/2026.1.5Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, under certain non-default configurations, processing of PDF uploads could be exploited to obtain RCE on the server. This issue is patched in 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5. |
Discourse
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| CVE-2026-47264 | Jun 12, 2026 |
Discourse <2026.1.4, <2026.3.1, <2026.4.1 Tag Group Leak by DetailedTagSerializerDiscourse is an open-source discussion platform. From versions 2026.1.0-latest to before 2026.1.4, 2026.3.0-latest to before 2026.3.1, and 2026.4.0-latest to before 2026.4.1, DetailedTagSerializer#tag_group_names returned every tag group a tag belonged to without filtering against the requesting user's visibility. With SiteSetting.tags_listed_by_group enabled, anonymous and unprivileged users hitting TagsController#info (which is exempt from requires_login) could read the names of tag groups restricted to specific user groups or non-visible categories. This issue has been patched in versions 2026.1.4, 2026.3.1, 2026.4.1, and 2026.5.0-latest.1. |
Discourse
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| CVE-2026-47263 | Jun 12, 2026 |
Discourse MsgBus Exposes Webhook Events (<=2026.4.1)Discourse is an open-source discussion platform. From versions 2026.1.0-latest to before 2026.1.4, 2026.3.0-latest to before 2026.3.1, and 2026.4.0-latest to before 2026.4.1, the MessageBus.publish call for /web_hook_events/<id> in Jobs::RedeliverWebHookEvents did not pass group_ids, leaving the channel readable by any authenticated user (or anonymous user on instances where login_required is disabled). Webhook IDs are sequential integers and trivially enumerable. This issue has been patched in versions 2026.1.4, 2026.3.1, 2026.4.1, and 2026.5.0-latest.1. |
Discourse
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| CVE-2026-45775 | Jun 12, 2026 |
Discourse pathtraversal backup download before 2026.1.4Discourse is an open-source discussion platform. From versions 2026.1.0-latest to before 2026.1.4, 2026.3.0-latest to before 2026.3.1, and 2026.4.0-latest to before 2026.4.1, a path traversal vulnerability in Discourse backup handling could allow an authenticated administrator on one site in a multisite deployment to access backup files belonging to another site when backups are stored locally. In affected configurations, an admin on Site A could potentially retrieve sensitive backup data from Site B (same host, multisite) by crafting a backup download request with a traversal payload. This issue has been patched in versions 2026.1.4, 2026.3.1, 2026.4.1, and 2026.5.0-latest.1. |
Discourse
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| CVE-2026-45085 | Jun 12, 2026 |
Discourse Chat Plugin Authorization/Disclosure Flaw (2026.1.02026.4.0)Discourse is an open-source discussion platform. From versions 2026.1.0-latest to before 2026.1.4, 2026.3.0-latest to before 2026.3.1, and 2026.4.0-latest to before 2026.4.1, four authorization/disclosure issues in the chat plugin (one also involving discourse-calendar): read-only category users could create chat threads, self-deleted chat messages could be restored by their author after channel access was revoked, moderators reviewing a flagged chat message were shown the channel's current last_message (often unrelated DM content), and calendar event payloads exposed the attached chat channel and its last message to viewers without chat access (including anonymous users). This affects sites with the chat plugin enabled; the calendar issue additionally requires discourse-calendar. This issue has been patched in versions 2026.1.4, 2026.3.1, 2026.4.1, and 2026.5.0-latest.1. |
Discourse
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| CVE-2026-44785 | Jun 12, 2026 |
Discourse AI explain permission bypass before v2026.4.1Discourse is an open-source discussion platform. From versions 2026.1.0-latest to before 2026.1.4, 2026.3.0-latest to before 2026.3.1, and 2026.4.0-latest to before 2026.4.1, the AI "explain" helper only checks can_see? on the post being explained, not its reply_to_post, so any authenticated user with access to the AI helper could read the raw contents of a hidden parent post by invoking "Explain" on a reply to it. This issue has been patched in versions 2026.1.4, 2026.3.1, 2026.4.1, and 2026.5.0-latest.1. |
Discourse
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| CVE-2026-44784 | Jun 12, 2026 |
Discourse 2026.12026.4.1: Group Owners Leak SMTP Credentials in History LogDiscourse is an open-source discussion platform. From versions 2026.1.0-latest to before 2026.1.4, 2026.3.0-latest to before 2026.3.1, and 2026.4.0-latest to before 2026.4.1, group owners who are not necessarily admins or moderators can view a group's outgoing email/SMTP credentials in plaintext via the group history log (/groups/:name/logs.json). Affected fields: email_password, email_username, smtp_server, smtp_port, smtp_ssl_mode. The most sensitive item is the SMTP password, which an owner could use to send mail as the group from outside Discourse. This impacts sites that have configured per-group SMTP credentials and granted group ownership to users who should not have access to those credentials. This issue has been patched in versions 2026.1.4, 2026.3.1, 2026.4.1, and 2026.5.0-latest.1. |
Discourse
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| CVE-2026-44783 | Jun 12, 2026 |
Discourse 2026.x Whispers Reply Auth BypassDiscourse is an open-source discussion platform. From versions 2026.1.0-latest to before 2026.1.4, 2026.3.0-latest to before 2026.3.1, and 2026.4.0-latest to before 2026.4.1, a flaw in how replies to whisper posts are handled allows authenticated users outside the groups configured in whispers_allowed_groups to post into a topic's staff-only whisper channel. The injected content is visible to whisperers (typically staff) alongside legitimate whispers. Only sites that have whispers enabled are affected. This issue has been patched in versions 2026.1.4, 2026.3.1, 2026.4.1, and 2026.5.0-latest.1. |
Discourse
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| CVE-2026-44782 | Jun 12, 2026 |
Discourse GrpPostSer: Misnamed Predicate Leaks Names (v2026.1.0-<2026.1.4)Discourse is an open-source discussion platform. From versions 2026.1.0-latest to before 2026.1.4, 2026.3.0-latest to before 2026.3.1, and 2026.4.0-latest to before 2026.4.1, GroupPostSerializer declared include_user_long_name? as the predicate for its :name attribute, but AMS looks for include_name?. The misnamed predicate was never called, so object.user.name was always serialized regardless of SiteSetting.enable_names. This issue has been patched in versions 2026.1.4, 2026.3.1, 2026.4.1, and 2026.5.0-latest.1. |
Discourse
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| CVE-2026-44780 | Jun 12, 2026 |
Discourse ReviewableQueuedPostSerializer raw_email leak 2026.13.0Discourse is an open-source discussion platform. From versions 2026.1.0-latest to before 2026.1.4, 2026.3.0-latest to before 2026.3.1, and 2026.4.0-latest to before 2026.4.1, ReviewableQueuedPostSerializer unconditionally included payload["raw_email"] for posts that arrived via incoming email. Category moderation group members reaching the review queue could therefore read the full inbound email source (headers, sender trace, MUA, body) without being in view_raw_email_allowed_groups the trust boundary that gates the dedicated raw-email endpoint. This issue has been patched in versions 2026.1.4, 2026.3.1, 2026.4.1, and 2026.5.0-latest.1. |
Discourse
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| CVE-2026-44779 | Jun 12, 2026 |
Discourse Bot Debug Log Disclosure v2026.1.0-2026.1.4Discourse is an open-source discussion platform. From versions 2026.1.0-latest to before 2026.1.4, 2026.3.0-latest to before 2026.3.1, and 2026.4.0-latest to before 2026.4.1, bot debug endpoints disclose whisper translation audit logs. This issue has been patched in versions 2026.1.4, 2026.3.1, 2026.4.1, and 2026.5.0-latest.1. |
Discourse
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| CVE-2026-44786 | Jun 12, 2026 |
Discourse MessageBus Unscoped Chat Pub (2026.1.3)Discourse is an open-source discussion platform. From versions 2026.1.0-latest to before 2026.1.4, 2026.3.0-latest to before 2026.3.1, and 2026.4.0-latest to before 2026.4.1, chat events for public category channels are published to MessageBus without permission scoping, so any MessageBus subscriber without chat enabled could receive chat message payloads in real time. This issue has been patched in versions 2026.1.4, 2026.3.1, 2026.4.1, and 2026.5.0-latest.1. |
Discourse
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| CVE-2026-34154 | May 19, 2026 |
Discourse Subscriptions Plugin: Unauthorized Access w/o Payment (2026.1.4)Discourse is an open-source discussion platform. In versions prior to 2026.1.4, 2026.3.1, 2026.4.1 and 2026.5.0-latest.1, a vulnerability in the discourse-subscriptions plugin allows users to gain access to subscription-gated groups without completing payment. This issue has been fixed in versions 2026.1.4, 2026.3.1, 2026.4.1 and 2026.5.0-latest.1. |
Discourse
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