by Kastro
Paper/Archive/CVE-2026-34838

CVE-2026-34838

Intermesh groupoffice — Group-Office: Authenticated Remote Code Execution via PHP Insecure Deserialization in `AbstractSettingsCollection`

EPSS 1%CVSS 10.0
critical.is priorityof 100
43
CVSS 10.0 (CNA)10.0 / 10 × 3030.0Not in CISA KEV+300.0EPSS percentile 64.1.641 × 2012.8No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

Group-Office is an enterprise customer relationship management and groupware tool. Prior to versions 6.8.156, 25.0.90, and 26.0.12, a vulnerability in the AbstractSettingsCollection model leads to insecure deserialization when these settings are loaded. By injecting a serialized FileCookieJar object into a setting string, an authenticated attacker can achieve Arbitrary File Write, leading directly to Remote Code Execution (RCE) on the server. This issue has been patched in versions 6.8.156, 25.0.90, and 26.0.12.

Affected

ProductAffectedFixed inSource
groupoffice< 6.8.156–CNA
groupoffice< 25.0.90–CNA
groupoffice< 26.0.12–CNA

Scores by source

GitHub_M (CNA)10.0CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
CISA ADPSSVCExploitation: none · Automatable: no · Technical impact: total

References

refgithub.com/Intermesh/groupoffice/security/advisories/GHSA-h22j-frrf-5vxqrefgithub.com/Intermesh/groupoffice/releases/tag/v25.0.90refgithub.com/Intermesh/groupoffice/releases/tag/v26.0.12refgithub.com/Intermesh/groupoffice/releases/tag/v6.8.156