Object injection in Roundcube Webmail session handling
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-502.
Summary
Roundcube Webmail from 1.6.0 before 1.6.20 and from 1.7.0 before 1.7.5 mishandles session keys that start with "!" in rcube_session::unserialize(), which is a deserialization flaw (CWE-502). The malformed session data desynchronizes parsing so that following session data is read as a serialized PHP value, enabling PHP object injection. A remote attacker without privileges can exploit it under high complexity if the attacker can influence stored session data.
Written with Claude Haiku 5.5 from the sources below · 2026-10-29
Description from the CNA
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
Upgrade Roundcube Webmail to 1.6.20 or 1.7.5, whichever matches the installed release line. The upstream fix rejects "!"-prefixed session keys.
Written with Claude Haiku 5.5 from the sources below · 2026-10-29
- Fix · CNA Webmail (Roundcube) Fixed in 1.6.20, 1.7.5
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Advisory ·
Roundcube Webmail — roundcube.net/news/2026/10/19/security-updates-1.6.20-and-1…
20 records Highest priority Priority LOW 20 LOW
Other records, highest priority first
- TI-2026-79180 Server-side request forgery filter bypass in Roundcube WebmailPriority LOW 38
- TI-2026-79177 Roundcube Webmail passes unsafe SVG and EPS content to ImageMagickPriority LOW 38
- TI-2026-79182 Improper authentication in Roundcube Webmail multi-host alias loginsPriority LOW 37
Vendor assessments
Timeline
- 2026-10-22 Threatist record created from CVE-2026-114724
- 2026-10-22 Alias added: GHSA-xxrc-hh9x-4pwx
- 2026-10-23 Affected versions changed · Red Hat
- 2026-10-23 CVSS score added · Red Hat
- 2026-10-23 Priority changed: MEDIUM → LOW
- 2026-10-28 CISA SSVC decision points changed
- 2026-10-29 CVSS score added · NVD
References
Patch 4
- https://github.com/roundcube/roundcubemail/commit/93284f3f0e13f99af37fc3b81861e142eea8a922
- https://github.com/roundcube/roundcubemail/releases/tag/1.7.5
- https://github.com/roundcube/roundcubemail/releases/tag/1.6.20
- https://github.com/roundcube/roundcubemail/commit/833770d3d3c35cfde74cc2614d368f25a75b6f99
More Roundcube Webmail vulnerabilities
- TI-2025-31204 Deserialization of untrusted data in Roundcube Webmail KEVCVSS 3.1CRITICAL 9.9
- TI-2021-19778 Roundcube before 1.3.17 and 1.4.x before 1.4.12 is prone to a potential SQL injection via search or search_params. KEVCVSS 3.1CRITICAL 9.8
- TI-2020-10051 rcube_image.php in Roundcube Webmail before 1.4.4 allows attackers to execute arbitrary… KEVCVSS 3.1CRITICAL 9.8
- TI-2024-28025 A Cross-Site Scripting vulnerability in Roundcube through 1.5.7 and 1.6.x through 1.6.7… KEVCVSS 3.1CRITICAL 9.3
- TI-2017-12250 Roundcube Webmail before 1.1.10, 1.2.x before 1.2.7, and 1.3.x before 1.3.3 allows… KEVCVSS 3.1HIGH 7.8
- TI-2025-41994 Cross-site scripting in Roundcube Webmail KEVCVSS 3.1HIGH 7.2
Sources
- CVE-2026-114724 · CVE Program
- CVE-2026-114724 · NVD
- FIRST EPSS
- GHSA-xxrc-hh9x-4pwx · GitHub Advisory Database · CC BY 4.0
- CVE-2026-114724 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences