CVE-2025-66376: Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting Vulnerability
High · CVSS 7.2 (CVSS 3.1)KEV known exploitedEPSS 20.2%, 97th percentilePublished Updated Assigner: mitre
In CISA’s Known Exploited Vulnerabilities catalog: Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting Vulnerability.
Added , federal remediation due . Known ransomware use: Unknown.
Required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Description
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.
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N · CWE-79
Status incidents that name it
No tracked status incident names this CVE.
Affected vendors and products
Zimbra: Collaboration
References
- CVE record on cve.org (opens in new tab)
- NVD entry (opens in new tab)
- wiki.zimbra.com/wiki/Security_Center (opens in new tab)
- wiki.zimbra.com/wiki/Zimbra_Releases/10.0.18 (opens in new tab)
- wiki.zimbra.com/wiki/Zimbra_Releases/10.1.13 (opens in new tab)
- wiki.zimbra.com/wiki/Zimbra_Responsible_Disclosure_Policy (opens in new tab)
- wiki.zimbra.com/wiki/Zimbra_Security_Advisories (opens in new tab)
- CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (opens in new tab)
- This product uses data from the NVD API but is not endorsed or certified by the NVD. (opens in new tab)
- Known Exploited Vulnerabilities catalog from CISA. (opens in new tab)
- EPSS scores from FIRST (Exploit Prediction Scoring System). (opens in new tab)