Roundcube Webmail before 1.6.20 and 1.7.x before 1.7.5 contains an object injection primitive in rcube_session::unserialize(). A session key prefixed with “!” was treated as having no value, and the reconstructed serialized string was emitted with a key but no corresponding value, desynchronizing the remainder of the input so that following session data was interpreted as a serialized value. This yields a PHP object injection primitive for an attacker able to influence stored session data. Upstream fixed this in the commit “Fix object injection primitive in rcube_session::unserialize() via “!”-prefixed session keys”, which rejects such keys.
Fix
Nothing published yet: no patch, vendor advisory or mitigation reference on NVD, no vendor advisory in the News for this CVE, not in CISA's KEV, no fixed package version. BaselineWatch does not guess at one.
Change history 7
- StatusUndergoing Analysis → PublishedNVD modified 2026-10-28 19:02
- StatusPublished → Undergoing AnalysisNVD modified 2026-10-28 19:17
- StatusUndergoing Analysis → PublishedNVD modified 2026-10-22 01:48
- StatusPublished → Undergoing AnalysisNVD modified 2026-10-22 16:45
- StatusReceived → PublishedNVD modified 2026-10-22 01:48
- StatusPublished → ReceivedNVD modified 2026-10-22 02:17
- First seenCVSS 7.4 · roundcubeNVD modified 2026-10-22 01:48
Affected (CPE criteria) 0
NVD has not attached CPE configurations yet.
References 6
- https://bugs.debian.org/1151279
- https://github.com/roundcube/roundcubemail/commit/833770d3d3c35cfde74cc2614d368f25a75b6f99
- https://github.com/roundcube/roundcubemail/commit/93284f3f0e13f99af37fc3b81861e142eea8a922
- https://github.com/roundcube/roundcubemail/releases/tag/1.6.20
- https://github.com/roundcube/roundcubemail/releases/tag/1.7.5
- https://roundcube.net/news/2026/10/19/security-updates-1.6.20-and-1.7.5