Critical 10.0Published Apr 2, 2026

CVE-2026-34838Group-Office: Authenticated Remote Code Execution via PHP Insecure Deserialization in `AbstractSettingsCollection`

Updated under an hour ago (Oct 26, 2026, 4:50 PM ET)

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It affects Intermesh groupoffice and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for Intermesh groupoffice

Exploited in the last 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.

CVSS: 10.0 CRITICAL (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Weakness (CWE): CWE-502
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Analyzed
Record last updated: Apr 3, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Intermesh groupoffice intermesh:groupoffice (from the name)	before 6.8.156; before 25.0.90; before 26.0.12	CNA record
intermesh group-office intermesh:group-office	before 6.8.156; from 25.0.1 before 25.0.90; from 26.0.1 before 26.0.12	NVD

References

References

https://github.com/Intermesh/groupoffice/security/advisories/GHSA-h22j-frrf-5vxq	x-refsource-confirm, vendor-advisory
https://github.com/Intermesh/groupoffice/releases/tag/v25.0.90	x-refsource-misc, release-notes
https://github.com/Intermesh/groupoffice/releases/tag/v26.0.12	x-refsource-misc, release-notes
https://github.com/Intermesh/groupoffice/releases/tag/v6.8.156	x-refsource-misc, release-notes

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.