Mozilla
Don't miss out!
Thousands of developers use stack.watch to stay informed.Get an email whenever new security vulnerabilities are reported in any Mozilla product.
RSS Feeds for Mozilla security vulnerabilities
Create a CVE RSS feed including security vulnerabilities found in Mozilla products with stack.watch. Just hit watch, then grab your custom RSS feed url.
Products by Mozilla Sorted by Most Security Vulnerabilities since 2018
Recent Mozilla Security Advisories
| Advisory | Title | Published |
|---|---|---|
| mfsa2025-54 | Security Vulnerabilities fixed in Thunderbird 140 mfsa2025-54 | July 2, 2025 |
| mfsa2025-55 | Security Vulnerabilities fixed in Thunderbird 128.12 mfsa2025-55 | June 30, 2025 |
| mfsa2025-52 | Security Vulnerabilities fixed in Firefox ESR 115.25 mfsa2025-52 | June 24, 2025 |
| mfsa2025-51 | Security Vulnerabilities fixed in Firefox 140 mfsa2025-51 | June 24, 2025 |
| mfsa2025-53 | Security Vulnerabilities fixed in Firefox ESR 128.12 mfsa2025-53 | June 24, 2025 |
| mfsa2025-50 | Security Vulnerabilities fixed in Thunderbird 139.0.2 mfsa2025-50 | June 10, 2025 |
| mfsa2025-49 | Security Vulnerabilities fixed in Thunderbird 128.11.1 mfsa2025-49 | June 10, 2025 |
| mfsa2025-47 | Security Vulnerabilities fixed in Firefox 139.0.4 mfsa2025-47 | June 10, 2025 |
| mfsa2025-48 | Security Issue fixed in Mozilla VPN for macOS v2.28.0 mfsa2025-48 | May 30, 2025 |
| mfsa2025-43 | Security Vulnerabilities fixed in Firefox ESR 115.24 mfsa2025-43 | May 27, 2025 |
Known Exploited Mozilla Vulnerabilities
The following Mozilla vulnerabilities have been marked by CISA as Known to be Exploited by threat actors.
| Title | Description | Added |
|---|---|---|
| Mozilla Firefox Use-After-Free Vulnerability |
Mozilla Firefox and Firefox ESR contain a use-after-free vulnerability in Animation timelines that allows for code execution in the content process. CVE-2024-9680 Exploit Probability: 11.7% |
October 15, 2024 |
| Mozilla Firefox, Firefox ESR, and Thunderbird Use-After-Free Vulnerability |
Mozilla Firefox, Firefox ESR, and Thunderbird contain a use-after-free vulnerability in SVG Animation, targeting Firefox and Tor browser users on Windows. CVE-2016-9079 Exploit Probability: 85.0% |
June 22, 2023 |
| Mozilla Firefox Security Feature Bypass Vulnerability |
Moxilla Firefox allows remote attackers to bypass the Same Origin Policy to read arbitrary files or gain privileges. CVE-2015-4495 Exploit Probability: 75.9% |
May 25, 2022 |
| Mozilla Firefox and Thunderbird Type Confusion Vulnerability |
Mozilla Firefox and Thunderbird contain a type confusion vulnerability that can occur when manipulating JavaScript objects due to issues in Array.pop, allowing for an exploitable crash. CVE-2019-11707 Exploit Probability: 84.2% |
May 23, 2022 |
| Mozilla Firefox and Thunderbird Sandbox Escape Vulnerability |
Mozilla Firefox and Thunderbird contain a sandbox escape vulnerability that could result in remote code execution. CVE-2019-11708 Exploit Probability: 65.7% |
May 23, 2022 |
| Mozilla Firefox and Thunderbird Denial-of-Service Vulnerability |
Mozilla Firefox and Thunderbird do not properly handle onreadystatechange events in conjunction with page reloading, which allows remote attackers to cause a denial-of-service or possibly execute arbitrary code via a crafted web site. CVE-2013-1690 Exploit Probability: 48.5% |
March 28, 2022 |
| Mozilla Firefox Use-After-Free Vulnerability |
Mozilla Firefox contains a use-after-free vulnerability in WebGPU IPC Framework which can be exploited to perform arbitrary code execution. CVE-2022-26486 Exploit Probability: 3.0% |
March 7, 2022 |
| Mozilla Firefox Use-After-Free Vulnerability |
Mozilla Firefox contains a use-after-free vulnerability in XSLT parameter processing which can be exploited to perform arbitrary code execution. CVE-2022-26485 Exploit Probability: 4.5% |
March 7, 2022 |
| Mozilla Firefox Information Disclosure Vulnerability |
Mozilla Firefox does not properly initialize data structures for the nsDOMSVGZoomEvent::mPreviousScale and nsDOMSVGZoomEvent::mNewScale functions, which allows remote attackers to obtain sensitive information from process memory via a crafted web site. CVE-2013-1675 Exploit Probability: 2.6% |
March 3, 2022 |
| Mozilla Firefox 74 and Firefox ESR 68.6 nsDocShell vulnerability |
A race condition can cause a use-after-free when running the nsDocShell destructor. This vulnerability affects Thunderbird < 68.7.0, Firefox < 74.0.1, and Firefox ESR < 68.6.1. CVE-2020-6819 Exploit Probability: 0.4% |
November 3, 2021 |
| Mozilla Firefox 74 and Firefox ESR 68.6 ReadableStream vulnerability |
A race condition can cause a use-after-free when handling a ReadableStream. This vulnerability affects Thunderbird < 68.7.0, Firefox < 74.0.1, and Firefox ESR < 68.6.1. CVE-2020-6820 Exploit Probability: 4.4% |
November 3, 2021 |
| Mozilla Firefox IonMonkey JIT compiler Type Confusion Vulnerability |
Incorrect alias information in IonMonkey JIT compiler for setting array elements could lead to a type confusion. This vulnerability affects Firefox ESR < 68.4.1, Thunderbird < 68.4.1, and Firefox < 72.0.1 CVE-2019-17026 Exploit Probability: 42.0% |
November 3, 2021 |
Of the known exploited vulnerabilities above, 2 are in the top 1%, or the 99th percentile of the EPSS exploit probability rankings. 4 known exploited Mozilla vulnerabilities are in the top 5% (95th percentile or greater) of the EPSS exploit probability rankings.
By the Year
In 2025 there have been 108 vulnerabilities in Mozilla with an average score of 7.7 out of ten. Last year, in 2024 Mozilla had 204 security vulnerabilities published. Right now, Mozilla is on track to have less security vulnerabilities in 2025 than it did last year. However, the average CVE base score of the vulnerabilities in 2025 is greater by 0.71.
| Year | Vulnerabilities | Average Score |
|---|---|---|
| 2025 | 108 | 7.75 |
| 2024 | 204 | 7.04 |
| 2023 | 200 | 7.20 |
| 2022 | 188 | 7.42 |
| 2021 | 158 | 7.11 |
| 2020 | 180 | 7.27 |
| 2019 | 144 | 7.67 |
| 2018 | 156 | 7.89 |
It may take a day or so for new Mozilla vulnerabilities to show up in the stats or in the list of recent security vulnerabilties. Additionally vulnerabilities may be tagged under a different product or component name.
Recent Mozilla Security Vulnerabilities
Firefox could have incorrectly parsed a URL and rewritten it to the youtube.com domain when parsing the URL specified in an `embed` tag
CVE-2025-6429
- June 24, 2025
Firefox could have incorrectly parsed a URL and rewritten it to the youtube.com domain when parsing the URL specified in an `embed` tag. This could have bypassed website security checks that restricted which domains users were allowed to embed. This vulnerability affects Firefox < 140, Firefox ESR < 128.12, Thunderbird < 140, and Thunderbird < 128.12.
The executable file warning did not warn users before opening files with the `terminal` extension
CVE-2025-6426
- June 24, 2025
The executable file warning did not warn users before opening files with the `terminal` extension. *This bug only affects Firefox for macOS. Other versions of Firefox are unaffected.* This vulnerability affects Firefox < 140, Firefox ESR < 128.12, Thunderbird < 140, and Thunderbird < 128.12.
An attacker who enumerated resources from the WebCompat extension could have obtained a persistent UUID
CVE-2025-6425
- June 24, 2025
An attacker who enumerated resources from the WebCompat extension could have obtained a persistent UUID that identified the browser, and persisted between containers and normal/private browsing mode, but not profiles. This vulnerability affects Firefox < 140, Firefox ESR < 115.25, Firefox ESR < 128.12, Thunderbird < 140, and Thunderbird < 128.12.
When Multi-Account Containers was enabled
CVE-2025-6432
- June 24, 2025
When Multi-Account Containers was enabled, DNS requests could have bypassed a SOCKS proxy when the domain name was invalid or the SOCKS proxy was not responding. This vulnerability affects Firefox < 140 and Thunderbird < 140.
A use-after-free in FontFaceSet resulted in a potentially exploitable crash
CVE-2025-6424
- June 24, 2025
A use-after-free in FontFaceSet resulted in a potentially exploitable crash. This vulnerability affects Firefox < 140, Firefox ESR < 115.25, Firefox ESR < 128.12, Thunderbird < 140, and Thunderbird < 128.12.
When a link can be opened in an external application, Firefox for Android will, by default, prompt the user before doing so
CVE-2025-6431
- June 24, 2025
When a link can be opened in an external application, Firefox for Android will, by default, prompt the user before doing so. An attacker could have bypassed this prompt, potentially exposing the user to security vulnerabilities or privacy leaks in external applications. *This bug only affects Firefox for Android. Other versions of Firefox are unaffected.* This vulnerability affects Firefox < 140.
When a URL was provided in a link querystring parameter, Firefox for Android would follow
CVE-2025-6428
- June 24, 2025
When a URL was provided in a link querystring parameter, Firefox for Android would follow that URL instead of the correct URL, potentially leading to phishing attacks. *This bug only affects Firefox for Android. Other versions of Firefox are unaffected.* This vulnerability affects Firefox < 140.
If a user saved a response from the Network tab in Devtools using the Save As context menu option
CVE-2025-6435
- June 24, 2025
If a user saved a response from the Network tab in Devtools using the Save As context menu option, that file may not have been saved with the `.download` file extension. This could have led to the user inadvertently running a malicious executable. This vulnerability affects Firefox < 140 and Thunderbird < 140.
An attacker was able to bypass the `connect-src` directive of a Content Security Policy by manipulating subdocuments
CVE-2025-6427
- June 24, 2025
An attacker was able to bypass the `connect-src` directive of a Content Security Policy by manipulating subdocuments. This would have also hidden the connections from the Network tab in Devtools. This vulnerability affects Firefox < 140 and Thunderbird < 140.
When a file download is specified via the `Content-Disposition` header
CVE-2025-6430
- June 24, 2025
When a file download is specified via the `Content-Disposition` header, that directive would be ignored if the file was included via a `<embed>` or `<object>` tag, potentially making a website vulnerable to a cross-site scripting attack. This vulnerability affects Firefox < 140, Firefox ESR < 128.12, Thunderbird < 140, and Thunderbird < 128.12.
The exception page for the HTTPS-Only feature, displayed when a website is opened via HTTP, lacked an anti-clickjacking delay, potentially
CVE-2025-6434
- June 24, 2025
The exception page for the HTTPS-Only feature, displayed when a website is opened via HTTP, lacked an anti-clickjacking delay, potentially allowing an attacker to trick a user into granting an exception and loading a webpage over HTTP. This vulnerability affects Firefox < 140 and Thunderbird < 140.
If a user visited a webpage with an invalid TLS certificate, and granted an exception, the webpage was able to provide a WebAuthn challenge
CVE-2025-6433
- June 24, 2025
If a user visited a webpage with an invalid TLS certificate, and granted an exception, the webpage was able to provide a WebAuthn challenge that the user would be prompted to complete. This is in violation of the WebAuthN spec which requires "a secure transport established without errors". This vulnerability affects Firefox < 140 and Thunderbird < 140.
Memory safety bugs present in Firefox 139 and Thunderbird 139
CVE-2025-6436
- June 24, 2025
Memory safety bugs present in Firefox 139 and Thunderbird 139. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 140 and Thunderbird < 140.
A vulnerability in Mozilla VPN on macOS allows privilege escalation from a normal user to root
CVE-2025-5687
- June 11, 2025
A vulnerability in Mozilla VPN on macOS allows privilege escalation from a normal user to root. *This bug only affects Mozilla VPN on macOS. Other operating systems are unaffected.* This vulnerability affects Mozilla VPN 2.28.0 < (macOS).
A crafted HTML email using mailbox:/// links
CVE-2025-5986
- June 11, 2025
A crafted HTML email using mailbox:/// links can trigger automatic, unsolicited downloads of .pdf files to the user's desktop or home directory without prompting, even if auto-saving is disabled. This behavior can be abused to fill the disk with garbage data (e.g. using /dev/urandom on Linux) or to leak Windows credentials via SMB links when the email is viewed in HTML mode. While user interaction is required to download the .pdf file, visual obfuscation can conceal the download trigger. Viewing the email in HTML mode is enough to load external content. This vulnerability affects Thunderbird < 128.11.1 and Thunderbird < 139.0.2.
An integer overflow was present in `OrderedHashTable` used by the JavaScript engine This vulnerability affects Firefox < 139.0.4.
CVE-2025-49710
- June 11, 2025
An integer overflow was present in `OrderedHashTable` used by the JavaScript engine This vulnerability affects Firefox < 139.0.4.
Certain canvas operations could have lead to memory corruption
CVE-2025-49709
- June 11, 2025
Certain canvas operations could have lead to memory corruption. This vulnerability affects Firefox < 139.0.4.
Due to insufficient escaping of the ampersand character in the Copy as cURL feature
CVE-2025-5265
- May 27, 2025
Due to insufficient escaping of the ampersand character in the Copy as cURL feature, an attacker could trick a user into using this command, potentially leading to local code execution on the user's system. *This bug only affects Firefox for Windows. Other versions of Firefox are unaffected.* This vulnerability affects Firefox < 139, Firefox ESR < 115.24, Firefox ESR < 128.11, Thunderbird < 139, and Thunderbird < 128.11.
Error handling for script execution was incorrectly isolated from web content, which could have allowed cross-origin leak attacks
CVE-2025-5263
- May 27, 2025
Error handling for script execution was incorrectly isolated from web content, which could have allowed cross-origin leak attacks. This vulnerability affects Firefox < 139, Firefox ESR < 115.24, Firefox ESR < 128.11, Thunderbird < 139, and Thunderbird < 128.11.
Memory safety bug present in Firefox ESR 128.10, and Thunderbird 128.10
CVE-2025-5269
- May 27, 2025
Memory safety bug present in Firefox ESR 128.10, and Thunderbird 128.10. This bug showed evidence of memory corruption and we presume that with enough effort this could have been exploited to run arbitrary code. This vulnerability affects Firefox ESR < 128.11 and Thunderbird < 128.11.
Memory safety bugs present in Firefox 138, Thunderbird 138, Firefox ESR 128.10, and Thunderbird 128.10
CVE-2025-5268
- May 27, 2025
Memory safety bugs present in Firefox 138, Thunderbird 138, Firefox ESR 128.10, and Thunderbird 128.10. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 139, Firefox ESR < 128.11, Thunderbird < 139, and Thunderbird < 128.11.
A clickjacking vulnerability could have been used to trick a user into leaking saved payment card details to a malicious page
CVE-2025-5267
- May 27, 2025
A clickjacking vulnerability could have been used to trick a user into leaking saved payment card details to a malicious page. This vulnerability affects Firefox < 139, Firefox ESR < 128.11, Thunderbird < 139, and Thunderbird < 128.11.
Script elements loading cross-origin resources generated load and error events which leaked information enabling XS-Leaks attacks
CVE-2025-5266
- May 27, 2025
Script elements loading cross-origin resources generated load and error events which leaked information enabling XS-Leaks attacks. This vulnerability affects Firefox < 139, Firefox ESR < 128.11, Thunderbird < 139, and Thunderbird < 128.11.
Due to insufficient escaping of the newline character in the Copy as cURL feature
CVE-2025-5264
- May 27, 2025
Due to insufficient escaping of the newline character in the Copy as cURL feature, an attacker could trick a user into using this command, potentially leading to local code execution on the user's system. This vulnerability affects Firefox < 139, Firefox ESR < 115.24, Firefox ESR < 128.11, Thunderbird < 139, and Thunderbird < 128.11.
Memory safety bugs present in Firefox 138 and Thunderbird 138
CVE-2025-5272
- May 27, 2025
Memory safety bugs present in Firefox 138 and Thunderbird 138. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 139 and Thunderbird < 139.
Previewing a response in Devtools ignored CSP headers, which could have allowed content injection attacks
CVE-2025-5271
- May 27, 2025
Previewing a response in Devtools ignored CSP headers, which could have allowed content injection attacks. This vulnerability affects Firefox < 139 and Thunderbird < 139.
In certain cases, SNI could have been sent unencrypted even when encrypted DNS was enabled
CVE-2025-5270
- May 27, 2025
In certain cases, SNI could have been sent unencrypted even when encrypted DNS was enabled. This vulnerability affects Firefox < 139 and Thunderbird < 139.
Opening maliciously-crafted URLs in Firefox from other apps such as Safari could have
CVE-2025-5020
- May 21, 2025
Opening maliciously-crafted URLs in Firefox from other apps such as Safari could have allowed attackers to spoof website addresses if the URLs utilized non-HTTP schemes used internally by the Firefox iOS client This vulnerability affects Firefox for iOS < 139.
An attacker was able to perform an out-of-bounds read or write on a JavaScript object by confusing array index sizes
CVE-2025-4919
- May 17, 2025
An attacker was able to perform an out-of-bounds read or write on a JavaScript object by confusing array index sizes. This vulnerability affects Firefox < 138.0.4, Firefox ESR < 128.10.1, Firefox ESR < 115.23.1, Thunderbird < 128.10.2, and Thunderbird < 138.0.2.
An attacker was able to perform an out-of-bounds read or write on a JavaScript `Promise` object
CVE-2025-4918
- May 17, 2025
An attacker was able to perform an out-of-bounds read or write on a JavaScript `Promise` object. This vulnerability affects Firefox < 138.0.4, Firefox ESR < 128.10.1, Firefox ESR < 115.23.1, Thunderbird < 128.10.2, and Thunderbird < 138.0.2.
Thunderbird parses addresses in a way that can allow sender spoofing in case the server allows an invalid From address to be used
CVE-2025-3875
- May 14, 2025
Thunderbird parses addresses in a way that can allow sender spoofing in case the server allows an invalid From address to be used. For example, if the From header contains an (invalid) value "Spoofed Name ", Thunderbird treats spoofed@example.com as the actual address. This vulnerability affects Thunderbird < 128.10.1 and Thunderbird < 138.0.1.
It was possible to craft an email that showed a tracking link as an attachment
CVE-2025-3932
- May 14, 2025
It was possible to craft an email that showed a tracking link as an attachment. If the user attempted to open the attachment, Thunderbird automatically accessed the link. The configuration to block remote content did not prevent that. Thunderbird has been fixed to no longer allow access to web pages listed in the X-Mozilla-External-Attachment-URL header of an email. This vulnerability affects Thunderbird < 128.10.1 and Thunderbird < 138.0.1.
Thunderbird's handling of the X-Mozilla-External-Attachment-URL header can be exploited to execute JavaScript in the file:/// context
CVE-2025-3909
- May 14, 2025
Thunderbird's handling of the X-Mozilla-External-Attachment-URL header can be exploited to execute JavaScript in the file:/// context. By crafting a nested email attachment (message/rfc822) and setting its content type to application/pdf, Thunderbird may incorrectly render it as HTML when opened, allowing the embedded JavaScript to run without requiring a file download. This behavior relies on Thunderbird auto-saving the attachment to /tmp and linking to it via the file:/// protocol, potentially enabling JavaScript execution as part of the HTML. This vulnerability affects Thunderbird < 128.10.1 and Thunderbird < 138.0.1.
Websites directing users to long URLs
CVE-2025-3859
6.1 - Medium
- April 30, 2025
Websites directing users to long URLs that caused eliding to occur in the location view could leverage the truncating behavior to potentially trick users into thinking they were on a different webpage This vulnerability affects Focus < 138.
Open Redirect
Due to insufficient escaping of special characters in the "copy as cURL" feature
CVE-2025-4089
- April 29, 2025
Due to insufficient escaping of special characters in the "copy as cURL" feature, an attacker could trick a user into using this command, potentially leading to local code execution on the user's system. This vulnerability affects Firefox < 138 and Thunderbird < 138.
A process isolation vulnerability in Thunderbird stemmed from improper handling of javascript: URIs, which could
CVE-2025-4083
- April 29, 2025
A process isolation vulnerability in Thunderbird stemmed from improper handling of javascript: URIs, which could allow content to execute in the top-level document's process instead of the intended frame, potentially enabling a sandbox escape. This vulnerability affects Firefox < 138, Firefox ESR < 128.10, Firefox ESR < 115.23, Thunderbird < 138, and Thunderbird < 128.10.
Thunderbird's update mechanism
CVE-2025-2817
- April 29, 2025
Thunderbird's update mechanism allowed a medium-integrity user process to interfere with the SYSTEM-level updater by manipulating the file-locking behavior. By injecting code into the user-privileged process, an attacker could bypass intended access controls, allowing SYSTEM-level file operations on paths controlled by a non-privileged user and enabling privilege escalation. This vulnerability affects Firefox < 138, Firefox ESR < 128.10, Firefox ESR < 115.23, Thunderbird < 138, and Thunderbird < 128.10.
A vulnerability existed in Thunderbird for Android where potentially sensitive library locations were logged via Logcat
CVE-2025-4090
- April 29, 2025
A vulnerability existed in Thunderbird for Android where potentially sensitive library locations were logged via Logcat. This vulnerability affects Firefox < 138 and Thunderbird < 138.
Memory safety bug present in Firefox ESR 128.9, and Thunderbird 128.9
CVE-2025-4093
- April 29, 2025
Memory safety bug present in Firefox ESR 128.9, and Thunderbird 128.9. This bug showed evidence of memory corruption and we presume that with enough effort this could have been exploited to run arbitrary code. This vulnerability affects Firefox ESR < 128.10 and Thunderbird < 128.10.
Due to insufficient escaping of the special characters in the "copy as cURL" feature
CVE-2025-4084
- April 29, 2025
Due to insufficient escaping of the special characters in the "copy as cURL" feature, an attacker could trick a user into using this command, potentially leading to local code execution on the user's system. *This bug only affects Firefox for Windows. Other versions of Firefox are unaffected.* This vulnerability affects Firefox ESR < 128.10, Firefox ESR < 115.23, and Thunderbird < 128.10.
Modification of specific WebGL shader attributes could trigger an out-of-bounds read
CVE-2025-4082
- April 29, 2025
Modification of specific WebGL shader attributes could trigger an out-of-bounds read, which, when chained with other vulnerabilities, could be used to escalate privileges. *This bug only affects Thunderbird for macOS. Other versions of Thunderbird are unaffected.* This vulnerability affects Firefox < 138, Firefox ESR < 128.10, Firefox ESR < 115.23, Thunderbird < 138, and Thunderbird < 128.10.
Memory safety bugs present in Firefox 137 and Thunderbird 137
CVE-2025-4092
- April 29, 2025
Memory safety bugs present in Firefox 137 and Thunderbird 137. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 138 and Thunderbird < 138.
A specially crafted filename containing a large number of encoded newline characters could obscure the file's extension when displayed in the download dialog
CVE-2025-4086
- April 29, 2025
A specially crafted filename containing a large number of encoded newline characters could obscure the file's extension when displayed in the download dialog. *This bug only affects Thunderbird for Android. Other versions of Thunderbird are unaffected.* This vulnerability affects Firefox < 138 and Thunderbird < 138.
An attacker with control over a content process could potentially leverage the privileged UITour actor to leak sensitive information or escalate privileges
CVE-2025-4085
- April 29, 2025
An attacker with control over a content process could potentially leverage the privileged UITour actor to leak sensitive information or escalate privileges. This vulnerability affects Firefox < 138 and Thunderbird < 138.
A vulnerability was identified in Thunderbird where XPath parsing could trigger undefined behavior due to missing null checks during attribute access
CVE-2025-4087
- April 29, 2025
A vulnerability was identified in Thunderbird where XPath parsing could trigger undefined behavior due to missing null checks during attribute access. This could lead to out-of-bounds read access and potentially, memory corruption. This vulnerability affects Firefox < 138, Firefox ESR < 128.10, Thunderbird < 138, and Thunderbird < 128.10.
A security vulnerability in Thunderbird allowed malicious sites to use redirects to send credentialed requests to arbitrary endpoints on any site
CVE-2025-4088
- April 29, 2025
A security vulnerability in Thunderbird allowed malicious sites to use redirects to send credentialed requests to arbitrary endpoints on any site that had invoked the Storage Access API. This enabled potential Cross-Site Request Forgery attacks across origins. This vulnerability affects Firefox < 138 and Thunderbird < 138.
Memory safety bugs present in Firefox 137, Thunderbird 137, Firefox ESR 128.9, and Thunderbird 128.9
CVE-2025-4091
- April 29, 2025
Memory safety bugs present in Firefox 137, Thunderbird 137, Firefox ESR 128.9, and Thunderbird 128.9. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 138, Firefox ESR < 128.10, Thunderbird < 138, and Thunderbird < 128.10.
By crafting a malformed file name for an attachment in a multipart message, an attacker
CVE-2025-2830
- April 15, 2025
By crafting a malformed file name for an attachment in a multipart message, an attacker can trick Thunderbird into including a directory listing of /tmp when the message is forwarded or edited as a new message. This vulnerability could allow attackers to disclose sensitive information from the victim's system. This vulnerability is not limited to Linux; similar behavior has been observed on Windows as well. This vulnerability affects Thunderbird < 137.0.2 and Thunderbird < 128.9.2.
Thunderbird processes the X-Mozilla-External-Attachment-URL header to handle attachments which can be hosted externally
CVE-2025-3522
- April 15, 2025
Thunderbird processes the X-Mozilla-External-Attachment-URL header to handle attachments which can be hosted externally. When an email is opened, Thunderbird accesses the specified URL to determine file size, and navigates to it when the user clicks the attachment. Because the URL is not validated or sanitized, it can reference internal resources like chrome:// or SMB share file:// links, potentially leading to hashed Windows credential leakage and opening the door to more serious security issues. This vulnerability affects Thunderbird < 137.0.2 and Thunderbird < 128.9.2.
When an email contains multiple attachments with external links
CVE-2025-3523
- April 15, 2025
When an email contains multiple attachments with external links via the X-Mozilla-External-Attachment-URL header, only the last link is shown when hovering over any attachment. Although the correct link is used on click, the misleading hover text could trick users into downloading content from untrusted sources. This vulnerability affects Thunderbird < 137.0.2 and Thunderbird < 128.9.2.