Description
Roundcube Webmail before 1.6.20 and 1.7.x before 1.7.5 is affected by an IMAP command injection vulnerability. A remote authenticated attacker can exploit this via CRLF sequences injected into the _flag parameter of the mail/mark action to execute arbitrary IMAP commands. Upstream fixed this in the commit “Fix IMAP command injection via CRLF in `_flag` parameter of mail/mark action”, which rejects flags containing control, whitespace and IMAP-special characters.
Affected products
roundcube: webmail
References6
- github.com/roundcube/roundcubemail/commit/242c6d6a150c850bd96d2… Patch
- github.com/roundcube/roundcubemail/commit/6c3c1897c11e193e47fcc… Patch
- bugs.debian.org/1151279 Third Party AdvisoryMailing List
- github.com/roundcube/roundcubemail/releases/tag/1.6.20 Release Notes
- github.com/roundcube/roundcubemail/releases/tag/1.7.5 Release Notes
- roundcube.net/news/2026/10/19/security-updates-1.6.20-and-1.7.5 Issue Tracking
Metrics
- CVSS 3.1
-
7.1
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N - EPSS — exploit probability
- 1% percentile: 57 · as of 8 November 2026
- CWE
- CWE-93
Could this be exploited in your environment?
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