Review reviewCritical

CVE-2026-34838

Intermesh groupoffice, group-office

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: 9.9
EPSS: 1.03%
CISA KEV: Not listed
Published: 2026.04.03

PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability1.03%

Technical severityCVSS 9.9

Vulnerability overview

Affected product and versions

Product: Intermesh groupoffice, group-office
Affected versions: >= < 6.8.156, >= < 25.0.90, >= < 26.0.12, < 6.8.156, >= 25.0.1 < 25.0.90, >= 26.0.1 < 26.0.12
Fixed versions: 6.8.156, 25.0.90, 26.0.12

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

1
Identify
Confirm that Intermesh groupoffice, group-office and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
CWE: CWE-502