CVE-2026-93642

Critical

Description

An unauthenticated sender can forge a share notification that triggers stored XSS when a signed-in Zimbra Modern recipient clicks Accept Share, allowing the attacker to access mailbox data and act as the victim.

SeverityCritical

CVSS9.3

Exploit probability—

Product

Zimbra Collaboration Suite (ZCS)

PublishedSep 25, 2026

First seenSep 25, 2026

Weakness typeCWE-79Cross-site scripting (XSS)

How to fix

Update

Zimbra Zimbra Collaboration Suite (ZCS)10.1.21 or later

Vendor advisories

wiki.zimbra.com/wiki/Zimbra_Security_Advisories

Affected products

Product	Affected versions	Fixed in
Zimbra Zimbra Collaboration Suite (ZCS)	v < 10.1.21	10.1.21

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