Threat Intelligence / CVE / CVE-2025-66376

CVE-2025-66376

CISA KEV

CVSS 7.2 (HIGH) · EPSS 10.0% · Published 2026-01-05

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 v3 vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

Weaknesses (CWE)

CWE-79

Threats tracking this CVE

Zimbra Collaboration Suite Stored XSS via CSS @import Active Exploitation (CVE-2025-66376) — Operation GhostMail — HIGH

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

Full detection coverage & IOCs for threats exploiting CVE-2025-66376 are available via the Threadlinqs MCP server (Purple tier). View plans →

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