CVE-2026-93647

EUVD-2026-87102
An unauthenticated calendar sender can place active markup in a COUNTER message's RFC From address. Selecting the message in Zimbra Classic triggers stored XSS, allowing the attacker to access mailbox data and act as the victim.
Cross-site Scripting
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
9.3 CRITICAL
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N
Awaiting analysis
This vulnerability is currently awaiting analysis.
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Common Weakness Enumeration
References
https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories