CVE-2025-66376

EUVD-2026-0850
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.
Cross-site Scripting
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
mitreCNA
7.2 HIGH
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: 93%
Affected Products (NVD)
VendorProductVersion
synacorzimbra_collaboration_suite
10.0.0 ≤
𝑥
< 10.0.18
synacorzimbra_collaboration_suite
10.1.0 ≤
𝑥
< 10.1.13
𝑥
= Vulnerable software versions
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
zimbracollaboration
10.0 ≤
𝑥
< 10.0.18
CNA
zimbracollaboration
10.1 ≤
𝑥
< 10.1.13
CNA
Common Weakness Enumeration
References
https://wiki.zimbra.com/wiki/Security_Center
https://wiki.zimbra.com/wiki/Zimbra_Releases/10.0.18#Security_Fixes
https://wiki.zimbra.com/wiki/Zimbra_Releases/10.1.13#Security_Fixes
https://wiki.zimbra.com/wiki/Zimbra_Responsible_Disclosure_Policy
https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-66376