Vulnerability 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.
CVSS Score
7.2
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Synacor | Zimbra Collaboration Suite | >= 10.0.0, < 10.0.18 |
Related Weaknesses (CWE)
References
- https://wiki.zimbra.com/wiki/Security_CenterRelease NotesVendor Advisory
- https://wiki.zimbra.com/wiki/Zimbra_Releases/10.0.18#Security_FixesRelease Notes
- https://wiki.zimbra.com/wiki/Zimbra_Releases/10.1.13#Security_FixesRelease Notes
- https://wiki.zimbra.com/wiki/Zimbra_Responsible_Disclosure_PolicyProduct
- https://wiki.zimbra.com/wiki/Zimbra_Security_AdvisoriesVendor Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-US Government Resource
FAQ
What is CVE-2025-66376?
CVE-2025-66376 is a vulnerability with a CVSS score of 7.2 (HIGH). 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.
How severe is CVE-2025-66376?
CVE-2025-66376 has been rated HIGH with a CVSS base score of 7.2/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2025-66376?
Check the references section above for vendor advisories and patch information. Affected products include: Synacor Zimbra Collaboration Suite.