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.
History

Mon, 28 Sep 2026 13:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Sat, 26 Sep 2026 23:00:00 +0000

Type Values Removed Values Added
First Time appeared Zimbra
Zimbra zimbra Collaboration Suite
Vendors & Products Zimbra
Zimbra zimbra Collaboration Suite

Fri, 25 Sep 2026 14:15:00 +0000

Type Values Removed Values Added
Description 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.
Title Zimbra Collaboration Suite Classic Web Client Stored Cross-Site Scripting via Crafted Calendar COUNTER Message From Address
Weaknesses CWE-79
References
Metrics cvssV3_1

{'score': 9.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: rapid7

Published: 2026-09-25T13:58:05.368Z

Updated: 2026-09-28T12:39:55.319Z

Reserved: 2026-09-18T12:22:43.194Z

Link: CVE-2026-93647

cve-icon Vulnrichment

Updated: 2026-09-28T12:39:52.413Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-09-25T14:17:23.673

Modified: 2026-09-29T21:29:07.663

Link: CVE-2026-93647

cve-icon Redhat

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