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CVE-2026-34838 - Vulnerability Analysis

CriticalCVSS: 9.9

Last Updated: April 2, 2026

Group-Office - Remote Code Execution

Published: April 2, 2026Updated: April 2, 2026Remote Exploitable

Overview

Group-Office < 6.8.156, < 25.0.90, < 26.0.12 contains an insecure deserialization vulnerability caused by injection of a serialized FileCookieJar object in AbstractSettingsCollection model, letting authenticated attackers achieve remote code execution.

Severity & Score

Severity: Critical

CVSS Score: 9.9

Impact

Authenticated attackers can execute arbitrary code remotely, potentially compromising the entire server.

Mitigation

Update to versions 6.8.156, 25.0.90, 26.0.12 or later.

References

https://github.com/Intermesh/groupoffice/releases/tag/v25.0.90
https://github.com/Intermesh/groupoffice/releases/tag/v26.0.12
https://github.com/Intermesh/groupoffice/releases/tag/v6.8.156
https://github.com/Intermesh/groupoffice/security/advisories/GHSA-h22j-frrf-5vxq

Related Resources

Vulnerability Intelligence Dashboard
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Details

CVE ID: CVE-2026-34838
Severity: Critical
CVSS Score: 9.9
Type: insecure_deserialization
Status: new

CWE

CWE-502

CVSS Metrics

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H