Description
Roundcube Webmail before 1.6.21 and 1.7.x before 1.7.6 contains an IMAP command injection vulnerability that allows attackers to inject commands via CRLF in the _uid parameter when messages_cache is enabled. Attackers can lure logged-in victims into opening crafted GET links to mail/show or mail/get, executing IMAP commands that delete messages, change flags, or grant mailbox access via SETACL.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Roundcube | Webmail | < 1.6.21, 1.7.0 – < 1.7.6 | 1.6.21 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | roundcube | No fix yet | — |
Show 6 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 26.04 LTS | roundcube | No fix yet | — |
| Ubuntu Pro 24.04 LTS | roundcube | No fix yet | — |
| Ubuntu Pro 22.04 LTS | roundcube | No fix yet | — |
| Ubuntu Pro 20.04 LTS | roundcube | No fix yet | — |
| Ubuntu Pro 18.04 LTS | roundcube | No fix yet | — |
| Ubuntu Pro 16.04 LTS | roundcube | No fix yet | — |
Advisories 1
- WID-SEC-2026-4533 Roundcube: Schwachstelle ermöglicht Manipulation von Dateien BSI CERT-Bund (WID) · Nov 11, 2026
References
- https://github.com/roundcube/roundcubemail/commit/4cb1cf106b9ca5d465ed4924f2fab5d5108edfeb patch
- https://github.com/roundcube/roundcubemail/commit/d1dda13597ceed9df49d434a8d88b758bcf6ef5c patch
- https://github.com/roundcube/roundcubemail/commit/2ea63692178cab5cea486c7c630901b7f6852c80 patch
- https://github.com/roundcube/roundcubemail/blob/1.7.5/program/lib/Roundcube/rcube_imap_generic.php#L2892 technical-description
- https://roundcube.net/news/2026/11/09/security-updates-1.6.21-and-1.7.6 vendor-advisory
- Webmail 1.6.21 Release Notes release-notes
- Webmail 1.7.6 Release Notes release-notes
- VulnCheck Advisory: Roundcube Webmail before 1.6.21 and 1.7.6 IMAP Command Injection via _uid third-party-advisory