CVE-2026-93641: CWE-79 Improper neutralization of input during web page generation ('cross-site scripting') in Zimbra Zimbra Collaboration Suite (ZCS)
An unauthenticated sender can forge a share notification that triggers stored XSS when a signed-in Zimbra Classic recipient clicks Accept Share, allowing the attacker to access mailbox data and act as the victim.
AI Analysis
Technical Summary
This vulnerability (CWE-79) in Zimbra Collaboration Suite (ZCS) allows an unauthenticated sender to craft a malicious share notification. When a signed-in Zimbra Classic recipient accepts the share, the stored XSS payload executes, enabling the attacker to access sensitive mailbox data and perform actions on behalf of the victim user. The flaw exists in versions prior to 10.1.21.
Potential Impact
Successful exploitation results in complete compromise of the victim's mailbox data confidentiality and integrity. The attacker can access mailbox contents and perform actions as the victim user. There is no impact on availability. The vulnerability requires user interaction (clicking Accept Share) but no authentication by the attacker.
Mitigation Recommendations
A fix is available in Zimbra Collaboration Suite version 10.1.21. Users and administrators should upgrade to version 10.1.21 or later to remediate this vulnerability. No vendor advisory content was provided, so check the official Zimbra security advisories for confirmation and additional guidance.
CVE-2026-93641: CWE-79 Improper neutralization of input during web page generation ('cross-site scripting') in Zimbra Zimbra Collaboration Suite (ZCS)
Description
An unauthenticated sender can forge a share notification that triggers stored XSS when a signed-in Zimbra Classic recipient clicks Accept Share, allowing the attacker to access mailbox data and act as the victim.
CVSS v3.1
Score 9.3critical
Affected software
Zimbra
Zimbra Collaboration Suite (ZCS)
pkg:github/zimbra/zimbra-collaboration-suiteRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CWE-79) in Zimbra Collaboration Suite (ZCS) allows an unauthenticated sender to craft a malicious share notification. When a signed-in Zimbra Classic recipient accepts the share, the stored XSS payload executes, enabling the attacker to access sensitive mailbox data and perform actions on behalf of the victim user. The flaw exists in versions prior to 10.1.21.
Potential Impact
Successful exploitation results in complete compromise of the victim's mailbox data confidentiality and integrity. The attacker can access mailbox contents and perform actions as the victim user. There is no impact on availability. The vulnerability requires user interaction (clicking Accept Share) but no authentication by the attacker.
Mitigation Recommendations
A fix is available in Zimbra Collaboration Suite version 10.1.21. Users and administrators should upgrade to version 10.1.21 or later to remediate this vulnerability. No vendor advisory content was provided, so check the official Zimbra security advisories for confirmation and additional guidance.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- rapid7
- Date Reserved
- 2026-09-18T12:22:38.559Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6ab67f25f7a7c54106db3e81
Added to database: 09/25/2026, 14:03:17 UTC
Last enriched: 09/25/2026, 14:17:40 UTC
Last updated: 09/26/2026, 03:15:09 UTC
Views: 15
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