CVE-2026-34838: Intermesh Group-Office

Critical severity, CVSS 9.9. EPSS: 1% chance of exploitation in the next 30 days.

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 products

• Intermesh Group-Office: before 6.8.156 (fixed in 6.8.156); from 25.0.1, before 25.0.90 (fixed in 25.0.90); from 26.0.1, before 26.0.12 (fixed in 26.0.12)

Published 2026-04-02. Last modified 2026-07-24.