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.
https://roundcube.net/news/2026/11/09/security-updates-1.6.21-and-1.7.6
https://github.com/roundcube/roundcubemail/releases/tag/1.7.6
https://github.com/roundcube/roundcubemail/releases/tag/1.6.21
https://github.com/roundcube/roundcubemail/commit/d1dda13597ceed9df49d434a8d88b758bcf6ef5c
https://github.com/roundcube/roundcubemail/commit/4cb1cf106b9ca5d465ed4924f2fab5d5108edfeb
https://github.com/roundcube/roundcubemail/commit/2ea63692178cab5cea486c7c630901b7f6852c80
Published: 2026-11-11
Updated: 2026-11-12
Base Score: 7.1
Vector: CVSS2#AV:N/AC:H/Au:N/C:C/I:C/A:N
Severity: High
Base Score: 6.8
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
Severity: Medium
Base Score: 7.4
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
Severity: High
EPSS: 0.0106