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Known Exploited Zimbra Vulnerabilities

The following Zimbra vulnerabilities have been marked by CISA as Known to be Exploited by threat actors.

Of the known exploited vulnerabilities above, 7 are in the top 1%, or the 99th percentile of the EPSS exploit probability rankings. The vulnerability CVE-2018-6882: Zimbra Collaboration Suite (ZCS) Cross-Site Scripting (XSS) Vulnerability is in the top 5% of the currently known exploitable vulnerabilities.

By the Year

In 2026 there have been 3 vulnerabilities in Zimbra with an average score of 5.8 out of ten. Last year, in 2025 Zimbra had 9 security vulnerabilities published. If vulnerabilities keep coming in at the current rate, it appears that number of security vulnerabilities in Zimbra in 2026 could surpass last years number. Last year, the average CVE base score was greater by 0.35

Recent Zimbra Security Vulnerabilities

CVE	Date	Vulnerability	Products
CVE-2025-71275	Mar 24, 2026	Zimbra ZCS 8.8.15 PostJournal CmdI via RCPT TO SMTP injection	Zimbra Collaboration Suite
CVE-2026-33371	Mar 20, 2026	Zimbra Collab XXE: EWS SOAP 10.0/10.1 Local File Disclosure An issue was discovered in Zimbra Collaboration (ZCS) 10.0 and 10.1. An XML External Entity (XXE) vulnerability exists in the Zimbra Exchange Web Services (EWS) SOAP interface due to improper handling of XML input. An authenticated attacker can submit crafted XML data that is processed by an XML parser with external entity resolution enabled. Successful exploitation may allow disclosure of sensitive local files from the server.	Zimbra Collaboration Suite
CVE-2025-66376	Jan 05, 2026	Zimbra ZCS 10 <10.0.18 / 10.1 <10.1.13 Classic UI XSS via CSS @import Zimbra Collaboration (ZCS) 10 before 10.0.18 and 10.1 before 10.1.13 allows Classic UI stored XSS via Cascading Style Sheets (CSS) @import directives in an HTML e-mail message.	Collaboration
CVE-2025-67809	Dec 15, 2025	Zimbra 10.0/10.1: Hardcoded Flickr API Creds Exposure An issue was discovered in Zimbra Collaboration (ZCS) 10.0 and 10.1. A hardcoded Flickr API key and secret are present in the publicly accessible Flickr Zimlet used by Zimbra Collaboration. Because these credentials are embedded directly in the Zimlet, any unauthorized party could retrieve them and misuse the Flickr integration. An attacker with access to the exposed credentials could impersonate the legitimate application and initiate valid Flickr OAuth flows. If a user is tricked into approving such a request, the attacker could gain access to the user s Flickr data. The hardcoded credentials have since been removed from the Zimlet code, and the associated key has been revoked.	Zimbra Collaboration Suite
CVE-2025-62763	Oct 21, 2025	Zimbra Chat Proxy SSRF in ZCS <10.1.12 Zimbra Collaboration (ZCS) before 10.1.12 allows SSRF because of the configuration of the chat proxy.	Collaboration
CVE-2025-54390	Sep 17, 2025	CSRF in Zimbra ResetPasswordRequest Enables Unauthorized Password Reset A Cross-Site Request Forgery (CSRF) vulnerability exists in the ResetPasswordRequest operation of Zimbra Collaboration (ZCS) when the zimbraFeatureResetPasswordStatus attribute is enabled. An attacker can exploit this by tricking an authenticated user into visiting a malicious webpage that silently sends a crafted SOAP request to reset the user's password. The vulnerability stems from a lack of CSRF token validation on the endpoint, allowing password resets without the user's consent.	Collaboration
CVE-2025-54391	Sep 16, 2025	CVE-2025-54391: Zimbra Collaboration 2FA Bypass via EnableTwoFactorAuthRequest SOAP A vulnerability in the EnableTwoFactorAuthRequest SOAP endpoint of Zimbra Collaboration (ZCS) allows an attacker with valid user credentials to bypass Two-Factor Authentication (2FA) protection. The attacker can configure an additional 2FA method (either a third-party authenticator app or email-based 2FA) without presenting a valid authentication token or proving access to an already configured 2FA method. This bypasses 2FA and results in unauthorized access to accounts that are otherwise protected by 2FA.	Zimbra Collaboration Suite
CVE-2024-45515	Jul 30, 2025	XSS in Zimbra Collaboration before 10.1; briefcase import metadata An issue was discovered in Zimbra Collaboration (ZCS) through 10.1. A Cross-Site Scripting (XSS) vulnerability exists in Zimbra webmail due to insufficient validation of the content type metadata when importing files into the briefcase. Attackers can exploit this issue by crafting a file with manipulated metadata, allowing them to bypass content type checks and execute arbitrary JavaScript within the victim's session.	Collaboration
CVE-2025-53645	Jul 09, 2025	Zimbra CS pre-10.1.9 DoS via Excessive Path Segments Zimbra Collaboration (ZCS) before 9.0.0 Patch 46, 10.0.x before 10.0.15, and 10.1.x before 10.1.9 is vulnerable to a denial of service condition due to improper handling of excessive, comma-separated path segments in the Admin Console. An unauthenticated remote attacker can send specially crafted GET requests that trigger redundant processing and inflated responses. This leads to uncontrolled resource consumption, resulting in denial of service.	Zimbra Collaboration Suite
CVE-2024-45516	May 14, 2025	Zimbra Classic UI XSS via <img> tags (before Patch 43, 10.1.4) An issue was discovered in Zimbra Collaboration (ZCS) 9.0.0 before Patch 43, 10.0.x before 10.0.12, 10.1.x before 10.1.4, and 8.8.15 before Patch 47. A Cross-Site Scripting (XSS) vulnerability in the Zimbra Classic UI allows attackers to execute arbitrary JavaScript within the user's session, potentially leading to unauthorized access to sensitive information. This issue arises from insufficient sanitization of HTML content, including malformed <img> tags with embedded JavaScript. The vulnerability is triggered when a user views a specially crafted email in the Classic UI, requiring no additional user interaction.	Zimbra Collaboration Suite
CVE-2025-27914	Mar 12, 2025	XSS in Zimbra 9.0-10.1 /h/rest endpoint An issue was discovered in Zimbra Collaboration (ZCS) 9.0 and 10.0 and 10.1. A Reflected Cross-Site Scripting (XSS) vulnerability exists in the /h/rest endpoint, allowing authenticated attackers to inject and execute arbitrary JavaScript in a victim's session. Exploitation requires a valid auth token and involves a crafted URL with manipulated query parameters that triggers XSS when accessed by a victim.	Collaboration
CVE-2025-27915	Mar 12, 2025	Stored XSS in Zimbra CWS v9.0-10.1 via Unsanitized iCal An issue was discovered in Zimbra Collaboration (ZCS) 9.0 and 10.0 and 10.1. A stored cross-site scripting (XSS) vulnerability exists in the Classic Web Client due to insufficient sanitization of HTML content in ICS files. When a user views an e-mail message containing a malicious ICS entry, its embedded JavaScript executes via an ontoggle event inside a <details> tag. This allows an attacker to run arbitrary JavaScript within the victim's session, potentially leading to unauthorized actions such as setting e-mail filters to redirect messages to an attacker-controlled address. As a result, an attacker can perform unauthorized actions on the victim's account, including e-mail redirection and data exfiltration.	Collaboration
CVE-2024-54663	Dec 19, 2024	Zimbra Collab LFI via /h/rest (9.0/10.0/10.1) An issue was discovered in the Webmail Classic UI in Zimbra Collaboration (ZCS) 9.0 and 10.0 and 10.1. A Local File Inclusion (LFI) vulnerability exists in the /h/rest endpoint, allowing authenticated remote attackers to include and access sensitive files in the WebRoot directory. Exploitation requires a valid auth token and involves crafting a malicious request targeting specific file paths.	Collaboration Server
CVE-2024-9665	Nov 22, 2024	Zimbra GraphQL CSRF Info Disclosure via Malicious Email Zimbra GraphQL Cross-Site Request Forgery Information Disclosure Vulnerability. This vulnerability allows remote attackers to disclose sensitive information on affected installations of Zimbra. User interaction is required to exploit this vulnerability in that the target must open a malicious email message. The specific flaw exists within the implementation of the graphql endpoint. The issue results from the lack of proper protections against cross-site request forgery (CSRF) attacks. An attacker can leverage this vulnerability to disclose information in the context of the target email account. Was ZDI-CAN-23939.	Zimbra Zimbra Collaboration Suite
CVE-2024-45194	Nov 21, 2024	Zimbra 9.0/10.0 Webmail XSS via Admin Panel In Zimbra Collaboration (ZCS) 9.0 and 10.0, a vulnerability in the Webmail Modern UI allows execution of stored Cross-Site Scripting (XSS) payloads. An attacker with administrative access to the Zimbra Administration Panel can inject malicious JavaScript code while configuring an email account. This injected code is stored on the server and executed in the context of the victim's browser when interacting with specific elements in the web interface. (The vulnerability can be mitigated by properly sanitizing input parameters to prevent the injection of malicious code.)	Zimbra Collaboration Suite
CVE-2024-45512	Nov 21, 2024	Zimbra Collab 10.1 XSS via Briefcase Folder Share An issue was discovered in webmail in Zimbra Collaboration (ZCS) through 10.1. An attacker can exploit this vulnerability by creating a folder in the Briefcase module with a malicious payload and sharing it with a victim. When the victim interacts with the folder share notification, the malicious script executes in their browser. This stored Cross-Site Scripting (XSS) vulnerability can lead to unauthorized actions within the victim's session.	Collaboration Server
CVE-2024-45518	Oct 22, 2024	SSRF RCE in Zimbra Collaboration 10.1.x (before 10.1.1) An issue was discovered in Zimbra Collaboration (ZCS) 10.1.x before 10.1.1, 10.0.x before 10.0.9, 9.0.0 before Patch 41, and 8.8.15 before Patch 46. It allows authenticated users to exploit Server-Side Request Forgery (SSRF) due to improper input sanitization and misconfigured domain whitelisting. This issue permits unauthorized HTTP requests to be sent to internal services, which can lead to Remote Code Execution (RCE) by chaining Command Injection within the internal service. When combined with existing XSS vulnerabilities, this SSRF issue can further facilitate Remote Code Execution (RCE).	Collaboration Zimbra Collaboration Suite
CVE-2024-45519	Oct 02, 2024	Zimbra PostJournal unauth exec before 10.1.1 The postjournal service in Zimbra Collaboration (ZCS) before 8.8.15 Patch 46, 9 before 9.0.0 Patch 41, 10 before 10.0.9, and 10.1 before 10.1.1 sometimes allows unauthenticated users to execute commands.	Collaboration Zimbra Collaboration Suite
CVE-2024-33536	Aug 12, 2024	Zimbra C&S 9.0/10.0 XSS via res param (JS injection) An issue was discovered in Zimbra Collaboration (ZCS) 9.0 and 10.0. The vulnerability occurs due to inadequate input validation of the res parameter, allowing an authenticated attacker to inject and execute arbitrary JavaScript code within the context of another user's browser session. By uploading a malicious JavaScript file, accessible externally, and crafting a URL containing its location in the res parameter, the attacker can exploit this vulnerability. Subsequently, when another user visits the crafted URL, the malicious JavaScript code is executed.	Collaboration
CVE-2024-33535	Aug 12, 2024	Zimbra C-10 LFI via packages param in ZCS 9.0/10.0 An issue was discovered in Zimbra Collaboration (ZCS) 9.0 and 10.0. The vulnerability involves unauthenticated local file inclusion (LFI) in a web application, specifically impacting the handling of the packages parameter. Attackers can exploit this flaw to include arbitrary local files without authentication, potentially leading to unauthorized access to sensitive information. The vulnerability is limited to files within a specific directory.	Collaboration
CVE-2024-33533	Aug 12, 2024	Zimbra Collab Suite 9.0/10.0 Reflected XSS via packages param An issue was discovered in Zimbra Collaboration (ZCS) 9.0 and 10.0, issue 1 of 2. A reflected cross-site scripting (XSS) vulnerability has been identified in the Zimbra webmail admin interface. This vulnerability occurs due to inadequate input validation of the packages parameter, allowing an authenticated attacker to inject and execute arbitrary JavaScript code within the context of another user's browser session. By uploading a malicious JavaScript file and crafting a URL containing its location in the packages parameter, the attacker can exploit this vulnerability. Subsequently, when another user visits the crafted URL, the malicious JavaScript code is executed.	Collaboration Zimbra Collaboration Suite
CVE-2024-27443	Aug 12, 2024	Zimbra XSS in CalendarInvite Header (v9.010.0) An issue was discovered in Zimbra Collaboration (ZCS) 9.0 and 10.0. A Cross-Site Scripting (XSS) vulnerability exists in the CalendarInvite feature of the Zimbra webmail classic user interface, because of improper input validation in the handling of the calendar header. An attacker can exploit this via an email message containing a crafted calendar header with an embedded XSS payload. When a victim views this message in the Zimbra webmail classic interface, the payload is executed in the context of the victim's session, potentially leading to execution of arbitrary JavaScript code.	Collaboration
CVE-2024-27442	Aug 12, 2024	Zimbra C2 LPE via zmmailboxdmgr (9.0/10.0) arg mishandling An issue was discovered in Zimbra Collaboration (ZCS) 9.0 and 10.0. The zmmailboxdmgr binary, a component of ZCS, is intended to be executed by the zimbra user with root privileges for specific mailbox operations. However, an attacker can escalate privileges from the zimbra user to root, because of improper handling of input arguments. An attacker can execute arbitrary commands with elevated privileges, leading to local privilege escalation.	Collaboration
CVE-2023-50808	Feb 13, 2024	DOM-based JS Injection in Zimbra Collaboration <9.0.0 Kepler Patch38 Zimbra Collaboration before Kepler 9.0.0 Patch 38 GA allows DOM-based JavaScript injection in the Modern UI.	Collaboration Zimbra Collaboration Suite
CVE-2023-48432	Feb 13, 2024	Zimbra XSS via maillink causing session theft (ZCS 8.8.15/9.0/10.0) An issue was discovered in Zimbra Collaboration (ZCS) 8.8.15, 9.0, and 10.0. XSS, with resultant session stealing, can occur via JavaScript code in a link (for a webmail redirection endpoint) within en email message, e.g., if a victim clicks on that link within Zimbra webmail.	Collaboration Zimbra Collaboration Suite
CVE-2023-45207	Feb 13, 2024	Zimbra C 8.8.15/9.0/10.x XSS thru PDF preview JS An issue was discovered in Zimbra Collaboration (ZCS) 8.8.15, 9.0, and 10.0. An attacker can send a PDF document through mail that contains malicious JavaScript. While previewing this file in webmail in the Chrome browser, the stored XSS payload is executed. (This has been mitigated by sanitising the JavaScript code present in a PDF document.)	Collaboration Zimbra Collaboration Suite
CVE-2023-45206	Feb 13, 2024	Zimbra Collaboration XSS via help endpoint (8.8.15-10.0) An issue was discovered in Zimbra Collaboration (ZCS) 8.8.15, 9.0, and 10.0. Through the help document endpoint in webmail, an attacker can inject JavaScript or HTML code that leads to cross-site scripting (XSS). (Adding an adequate message to avoid malicious code will mitigate this issue.)	Collaboration
CVE-2023-26562	Feb 13, 2024	Zimbra Collaboration Server 8.8.15/9.0 Account Closure Bypass via IMAP/SMTP In Zimbra Collaboration (ZCS) 8.8.15 and 9.0, a closed account (with 2FA and generated passwords) can send e-mail messages when configured for Imap/smtp.	Collaboration Collaboration Server
CVE-2017-20188	Jan 02, 2024	Zimbra zm-ajax <8.8.1 XSS via XFormItem.setError A vulnerability has been found in Zimbra zm-ajax up to 8.8.1 and classified as problematic. Affected by this vulnerability is the function XFormItem.prototype.setError of the file WebRoot/js/ajax/dwt/xforms/XFormItem.js. The manipulation of the argument message leads to cross site scripting. The attack can be launched remotely. The complexity of an attack is rather high. The exploitation appears to be difficult. Upgrading to version 8.8.2 is able to address this issue. The identifier of the patch is 8d039d6efe80780adc40c6f670c06d21de272105. It is recommended to upgrade the affected component. The identifier VDB-249421 was assigned to this vulnerability.	Zm Ajax
CVE-2023-43102	Dec 07, 2023	ZCS <10.0.4 XSS allows authenticated mailbox access An issue was discovered in Zimbra Collaboration (ZCS) before 10.0.4. An XSS issue can be exploited to access the mailbox of an authenticated user. This is also fixed in 8.8.15 Patch 43 and 9.0.0 Patch 36.	Collaboration
CVE-2023-43103	Dec 07, 2023	XSS via unsanitized param in Zimbra ZCS before 10.0.4 (8.8.15/9.0.0 fixes) An XSS issue was discovered in a web endpoint in Zimbra Collaboration (ZCS) before 10.0.4 via an unsanitized parameter. This is also fixed in 8.8.15 Patch 43 and 9.0.0 Patch 36.	Collaboration
CVE-2023-41106	Dec 07, 2023	Zimbra Collaboration Server <10.0.3 Account Credential Disclosure An issue was discovered in Zimbra Collaboration (ZCS) before 10.0.3. An attacker can gain access to a Zimbra account. This is also fixed in 9.0.0 Patch 35 and 8.8.15 Patch 42.	Collaboration
CVE-2023-37580	Jul 31, 2023	Zimbra XSS in Classic Web Client <8.8.15 Patch 41 Zimbra Collaboration (ZCS) 8 before 8.8.15 Patch 41 allows XSS in the Zimbra Classic Web Client.	Zimbra
CVE-2023-38750	Jul 31, 2023	Zimbra CWS / v8-10 JSP/XML Exposure (before 8.8.15p41/9.0.0p34/10.0.2) In Zimbra Collaboration (ZCS) 8 before 8.8.15 Patch 41, 9 before 9.0.0 Patch 34, and 10 before 10.0.2, internal JSP and XML files can be exposed.	Zimbra Zimbra Collaboration Suite
CVE-2023-34193	Jul 06, 2023	Zimbra ZCS 8.8.15 File Upload Vulnerability in ClientUploader - RCE File Upload vulnerability in Zimbra ZCS 8.8.15 allows an authenticated privileged user to execute arbitrary code and obtain sensitive information via the ClientUploader function.	Collaboration
CVE-2023-29381	Jul 06, 2023	Zimbra Collaboration Server 8.8.15 Privilege Escalation via Pwd & 2FA An issue in Zimbra Collaboration (ZCS) v.8.8.15 and v.9.0 allows a remote attacker to escalate privileges and obtain sensitive information via the password and 2FA parameters.	Collaboration
CVE-2023-29382	Jul 06, 2023	Zimbra Collaboration Suite v8.8.15/v9.0 sfdc_preauth.jsp Remote Code Exec An issue in Zimbra Collaboration ZCS v.8.8.15 and v.9.0 allows an attacker to execute arbitrary code via the sfdc_preauth.jsp component.	Collaboration
CVE-2023-34192	Jul 06, 2023	XSS in Zimbra ZCS 8.8.15 /h/autoSaveDraft Allows Remote Auth'd Attacker Cross Site Scripting vulnerability in Zimbra ZCS v.8.8.15 allows a remote authenticated attacker to execute arbitrary code via a crafted script to the /h/autoSaveDraft function.	Collaboration
CVE-2023-24030	Jun 15, 2023	Zimbra CS 9.0/8.8.15 Open Redirect via /preauth An open redirect vulnerability exists in the /preauth Servlet in Zimbra Collaboration Suite through 9.0 and 8.8.15. To exploit the vulnerability, an attacker would need to have obtained a valid zimbra auth token or a valid preauth token. Once the token is obtained, an attacker could redirect a user to any URL if url sanitisation is bypassed in incoming requests. NOTE: this is similar, but not identical, to CVE-2021-34807.	Collaboration Zimbra Collaboration Suite
CVE-2023-24031	Jun 15, 2023	Zimbra ZCS 9.0/8.8.15 XSS via /h/ Attr An issue was discovered in Zimbra Collaboration (ZCS) 9.0 and 8.8.15. XSS can occur, via one of attributes of the webmail /h/ endpoint, to execute arbitrary JavaScript code, leading to information disclosure.	Collaboration
CVE-2023-24032	Jun 15, 2023	Zimbra 9.0/8.8.15 JVM Arg LPE (Priv Esc) In Zimbra Collaboration Suite through 9.0 and 8.8.15, an attacker (who has initial user access to a Zimbra server instance) can execute commands as root by passing one of JVM arguments, leading to local privilege escalation (LPE).	Collaboration Zimbra Collaboration Suite
CVE-2022-45911	Jan 06, 2023	Zimbra Collaboration 9.0 Classic UI XSS via Username Field An issue was discovered in Zimbra Collaboration (ZCS) 9.0. XSS can occur on the Classic UI login page by injecting arbitrary JavaScript code in the username field. This occurs before the user logs into the system, which means that even if the attacker executes arbitrary JavaScript, they will not get any sensitive information.	Collaboration Zimbra Collaboration Suite
CVE-2022-45913	Jan 06, 2023	XSS via URL Attributes in Zimbra ZCS 9.0 Webmail An issue was discovered in Zimbra Collaboration (ZCS) 9.0. XSS can occur via one of attributes in webmail URLs to execute arbitrary JavaScript code, leading to information disclosure.	Collaboration Zimbra Collaboration Suite
CVE-2022-45912	Dec 05, 2022	ZCS 8.8.15/9.0 RCE via ClientUploader Auth Admin An issue was discovered in Zimbra Collaboration (ZCS) 8.8.15 and 9.0. Remote code execution can occur through ClientUploader by an authenticated admin user. An authenticated admin user can upload files through the ClientUploader utility, and traverse to any other directory for remote code execution.	Collaboration Collaboration Server
CVE-2022-41349	Oct 12, 2022	Reflected XSS via /h/compose attachUrl in Zimbra 8.8.15 In Zimbra Collaboration Suite (ZCS) 8.8.15, the URL at /h/compose accepts an attachUrl parameter that is vulnerable to Reflected XSS. This allows executing arbitrary JavaScript on the victim's machine.	Collaboration
CVE-2022-41348	Oct 12, 2022	Zimbra ZCS 9.0 XSS via IMG onerror Info Disclosure An issue was discovered in Zimbra Collaboration (ZCS) 9.0. XSS can occur via the onerror attribute of an IMG element, leading to information disclosure.	Collaboration
CVE-2022-41351	Oct 12, 2022	XSS via view param in Zimbra Collaboration Suite 8.8.15 (calendar) In Zimbra Collaboration Suite (ZCS) 8.8.15, at the URL /h/calendar, one can trigger XSS by adding JavaScript code to the view parameter and changing the value of the uncheck parameter to a string (instead of default value of 10).	Collaboration Zimbra Collaboration Suite
CVE-2022-41350	Oct 12, 2022	ZCS 8.8.15 RefXSS via /h/search?phone in voicemail module In Zimbra Collaboration Suite (ZCS) 8.8.15, /h/search?action=voicemail&action=listen accepts a phone parameter that is vulnerable to Reflected XSS. This allows executing arbitrary JavaScript on the victim's machine.	Collaboration
CVE-2022-41352	Sep 26, 2022	Zimbra (ZCS) 8.8.15/9.0 File Upload via amavis Cpio Loophole An issue was discovered in Zimbra Collaboration (ZCS) 8.8.15 and 9.0. An attacker can upload arbitrary files through amavis via a cpio loophole (extraction to /opt/zimbra/jetty/webapps/zimbra/public) that can lead to incorrect access to any other user accounts. Zimbra recommends pax over cpio. Also, pax is in the prerequisites of Zimbra on Ubuntu; however, pax is no longer part of a default Red Hat installation after RHEL 6 (or CentOS 6). Once pax is installed, amavis automatically prefers it over cpio.	Collaboration Zimbra Collaboration Suite
CVE-2022-41347	Sep 26, 2022	Zimbra Collaboration 8.8.x/9.x: sudo allows zimbra to run NGINX as root An issue was discovered in Zimbra Collaboration (ZCS) 8.8.x and 9.x (e.g., 8.8.15). The Sudo configuration permits the zimbra user to execute the NGINX binary as root with arbitrary parameters. As part of its intended functionality, NGINX can load a user-defined configuration file, which includes plugins in the form of .so files, which also execute as root.	Collaboration