Zimbra Collaboration Suite vulnerabilitiesAnd the versions its exploited flaws hit.
Zimbra Collaboration Suite is made by Synacor. We track 62 published vulnerabilities in it, across 93 versions. 10 of them are on the list of flaws known to be exploited, the newest added on 18 March 2026. If you run Zimbra Collaboration Suite, check your version against the exploited flaws below and patch those first.
The most recent Zimbra Collaboration Suite flaw added to the known-exploited list is CVE-2025-66376, on 18 March 2026. We keep watching the known-exploited list.
Which versions of Zimbra Collaboration Suite do the exploited flaws hit?
Each exploited flaw lists the versions it affects, usually as ranges. "10.0.0 to before 10.0.18" means from 10.0.0 up to, but not including, 10.0.18. Find your version, then patch.
- CVE-2025-66376Exploited list, 18 Mar 2026
Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting Vulnerability
10.0.0 to before 10.0.1810.1.0 to before 10.1.13 - CVE-2020-7796Exploited list, 17 Feb 2026
Synacor Zimbra Collaboration Suite (ZCS) Server-Side Request Forgery Vulnerability
before 8.8.158.8.158.8.15-p18.8.15-p28.8.15-p38.8.15-p48.8.15-p58.8.15-p6 - CVE-2019-9621Exploited list, 7 Jul 2025
Synacor Zimbra Collaboration Suite (ZCS) Server-Side Request Forgery (SSRF) Vulnerability
before 8.6.08.6.08.6.0-patch18.6.0-patch28.6.0-patch38.6.0-patch48.6.0-patch58.6.0-patch6 - CVE-2023-34192Exploited list, 25 Feb 2025
Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting (XSS) Vulnerability
8.8.158.8.15-p18.8.15-p28.8.15-p38.8.15-p48.8.15-p58.8.15-p68.8.15-p7 - CVE-2023-37580Exploited list, 27 Jul 2023
Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting (XSS) Vulnerability
8.8.0 to before 8.8.158.8.15-p38.8.15-p58.8.15-p118.8.15-p268.8.15-p308.8.15-p318.8.15-p32 - CVE-2022-27926Exploited list, 3 Apr 2023
Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting (XSS) Vulnerability
9.0.09.0.0-p19.0.0-p29.0.0-p39.0.0-p49.0.0-p59.0.0-p69.0.0-p7 - CVE-2022-27925Exploited list, 11 Aug 2022
Synacor Zimbra Collaboration Suite (ZCS) Arbitrary File Upload Vulnerability
8.8.158.8.15-p18.8.15-p28.8.15-p38.8.15-p48.8.15-p58.8.15-p68.8.15-p7 - CVE-2022-27924Exploited list, 4 Aug 2022
Synacor Zimbra Collaboration Suite (ZCS) Command Injection Vulnerability
8.8.158.8.15-p18.8.15-p28.8.15-p38.8.15-p48.8.15-p58.8.15-p68.8.15-p7 - CVE-2018-6882Exploited list, 19 Apr 2022
Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting (XSS) Vulnerability
before 8.7.08.7.08.8.08.8.18.8.28.8.38.8.48.8.5 - CVE-2019-9670Exploited list, 10 Jan 2022
Synacor Zimbra Collaboration Suite (ZCS) Improper Restriction of XML External Entity Reference
8.7.0 to before 8.7.118.7.118.7.11-p18.7.11-p28.7.11-p38.7.11-p48.7.11-p58.7.11-p6
Which Zimbra Collaboration Suite vulnerabilities are being exploited?
10 flaws are on the government list of vulnerabilities known to be exploited. These are the ones criminals are using now, so they go first, whatever their severity score says.
- 7.2Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting Vulnerability
Synacor Zimbra Collaboration Suite (ZCS) contains a cross-site scripting vulnerability in the Classic UI where attackers could abuse Cascading Style Sheets (CSS) @import directives in email HTML.
- 9.8Synacor Zimbra Collaboration Suite (ZCS) Server-Side Request Forgery Vulnerability
Synacor Zimbra Collaboration Suite (ZCS) contains a server-side request forgery vulnerability if WebEx zimlet installed and zimlet JSP is enabled.
- 7.5Synacor Zimbra Collaboration Suite (ZCS) Server-Side Request Forgery (SSRF) Vulnerability
Synacor Zimbra Collaboration Suite (ZCS) contains a server-side request forgery (SSRF) vulnerability via the ProxyServlet component.
- 9.0Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting (XSS) Vulnerability
Synacor Zimbra Collaboration Suite (ZCS) contains a cross-site scripting (XSS) vulnerability that allows a remote authenticated attacker to execute arbitrary code via a crafted script to the /h/autoSaveDraft function.
- 6.1Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting (XSS) Vulnerability
Synacor Zimbra Collaboration Suite (ZCS) contains a cross-site scripting vulnerability impacting the confidentiality and integrity of data.
- 6.1Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting (XSS) Vulnerability
Synacor Zimbra Collaboration Suite (ZCS) contains a cross-site scripting vulnerability by allowing an endpoint URL to accept parameters without sanitizing.
- 7.2Synacor Zimbra Collaboration Suite (ZCS) Arbitrary File Upload Vulnerability
Synacor Zimbra Collaboration Suite (ZCS) contains flaw in the mboximport functionality, allowing an authenticated attacker to upload arbitrary files to perform remote code execution.
- 7.5Synacor Zimbra Collaboration Suite (ZCS) Command Injection Vulnerability
Synacor Zimbra Collaboration Suite (ZCS) allows an attacker to inject memcache commands into a targeted instance which causes an overwrite of arbitrary cached entries.
Which Zimbra Collaboration Suite flaws are most likely to be used?
Ranked by the latest exploit-likelihood forecast: the chance each flaw is used in an attack in the next 30 days. A high severity score on its own doesn't tell you that. Flaws shared by many other makers' products are left out.
- >99%
mailboxd component in Synacor Zimbra Collaboration Suite 8.7.x before 8.7.11p10 has an XML External Entity injection (XXE) vulnerability, as demonstrated by Autodiscover/Autodiscover.xml.
- 99%
Zimbra Collaboration (aka ZCS) 8.8.15 and 9.0 has mboximport functionality that receives a ZIP archive and extracts files from it.
- 94%
Zimbra Collaboration (aka ZCS) 8.8.15 and 9.0 allows an unauthenticated attacker to inject arbitrary memcache commands into a targeted instance.
- 86%CVE-2013-7091Medium
Directory traversal vulnerability in /res/I18nMsg,AjxMsg,ZMsg,ZmMsg,AjxKeys,ZmKeys,ZdMsg,Ajx%20TemplateMsg.js.zgz in Zimbra 7.2.2 and 8.0.2 allows remote attackers to read arbitrary files via a ..
- 84%
Zimbra Collaboration Suite (ZCS) before 8.8.15 Patch 7 allows SSRF when WebEx zimlet is installed and zimlet JSP is enabled.
- 81%
Zimbra Collaboration Suite before 8.6 patch 13, 8.7.x before 8.7.11 patch 10, and 8.8.x before 8.8.10 patch 7 or 8.8.x before 8.8.11 patch 3 allows SSRF via the ProxyServlet component.
- 77%
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.
- 49%
Zimbra Collaboration (ZCS) 8 before 8.8.15 Patch 41 allows XSS in the Zimbra Classic Web Client.
- 37%CVE-2025-25064High
SQL injection vulnerability in the ZimbraSync Service SOAP endpoint in Zimbra Collaboration 10.0.x before 10.0.12 and 10.1.x before 10.1.4 due to insufficient sanitization of a user-supplied parameter.
- 30%
Cross-site scripting (XSS) vulnerability in the ZmMailMsgView.getAttachmentLinkHtml function in Zimbra Collaboration Suite (ZCS) before 8.7 Patch 1 and 8.8.x before 8.8.7 might allow remote attackers to inject...
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1 flaw being exploited affects software Acme tracks
Synacor Zimbra Collaboration Suite (ZCS) contains a cross-site scripting vulnerability in the Classic UI where attackers could abuse Cascading Style Sheets (CSS) @import directives in email HTML.
- Matched to
- Zimbra Collaboration Suite on Acme's software list
- What to do
- Patch first, then check for signs of use
Sent to the alert recipients Acme chose. Also in the app and to Acme's webhook.
We track 62 published vulnerabilities listed under the name Zimbra Collaboration Suite, across 93 versions. The most recent Zimbra Collaboration Suite flaw added to the known-exploited list is CVE-2025-66376, on 18 March 2026.
10 are on the list of flaws known to be exploited. The most recently added are CVE-2025-66376, CVE-2020-7796 and CVE-2019-9621.
Each flaw names its own versions, usually as ranges. The newest, CVE-2025-66376, affects 10.0.0 to before 10.0.18, 10.1.0 to before 10.1.13. The versions for every exploited flaw are listed on this page.
Create a Precursor Intelligence account and track Zimbra Collaboration Suite. We match it against every published flaw, give each one a risk score from 0 to 100 and keep watching, so you hear about new ones as soon as we know, by email, in the app or by webhook.