CVE-2026-66911
Stored Cross-Site Scripting in Zimbra
- State
- Published
- Severity
- 5.3 Medium
- Published
- Oct 29, 2026
- Updated
- Oct 29, 2026
- Reserved
- Jul 28, 2026
Description
Zimbra is vulnerable to stored cross-site scripting (XSS) via the Content-Location MIME header in email attachments. Due to lack of sanitization of the Content-Location header, an attacker can set it to a javascript: URI. An unauthenticated remote attacker can send a crafted email to a victim; when the victim opens the email in the Zimbra web interface and clicks the attachment name, the JavaScript payload executes in the victim's browser context. This issue was fixed in version 10.1.21
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 5.3 Medium | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N | CERT-PL |
Weaknesses
- CWE-79 Improper neutralization of input during web page generation ('cross-site scripting')
Affected Products
| Product | Versions |
|---|---|
Zimbra CollaborationSynacor |
|
References
- https://cert.pl/en/posts/2026/10/CVE-2026-66911third-party-advisory
- https://wiki.zimbra.com/wiki/Zimbra_Security_Advisoriesrelease-notes
Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.