Read the docs

Object injection in Roundcube Webmail session handling

Priority LOW 37CWE-502Published · Updated

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

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00407 35th percentileScored 2026-11-07
Fix Fixed Webmail (Roundcube): 1.6.20, 1.7.5

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

VendorProductAffected versionsFixed inStatusSource
RoundcubeWebmail1.6.0 to before 1.6.20; 1.7.0 to before 1.7.51.6.20, 1.7.5Patch availableCNA
  • Webmail VendorRoundcube Affected 1.6.0 to before 1.6.20; 1.7.0 to before 1.7.5 Fixed in 1.6.20, 1.7.5 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:roundcube:webmail:*:*:*:*:*:*:*:*1.6.0 to before 1.6.20; 1.7.0 to before 1.7.5VulnerableRoundcube
  • cpe:2.3:a:roundcube:webmail:*:*:*:*:*:*:*:* Versions 1.6.0 to before 1.6.20; 1.7.0 to before 1.7.5 Vulnerable ·Roundcube

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

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-22 Threatist record created from CVE-2026-114724
  2. 2026-10-22 Alias added: GHSA-xxrc-hh9x-4pwx
  3. 2026-10-23 Affected versions changed · Red Hat
  4. 2026-10-23 CVSS score added · Red Hat
  5. 2026-10-23 Priority changed: MEDIUM → LOW
  6. 2026-10-28 CISA SSVC decision points changed
  7. 2026-10-29 CVSS score added · NVD

References

  • 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
See all 112 →

Sources