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
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Synacor | Zimbra Collaboration | < 10.1.21 | 10.1.21 |
Advisories 1
- WID-SEC-2026-3593 Synacor Zimbra: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 29, 2026
References
- https://cert.pl/en/posts/2026/10/CVE-2026-66911 third-party-advisory
- https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories release-notes