CVE-2026-27947

Received Received - Intake

Authenticated Remote Code Execution in Group-Office TNEF Processing

Publication date: 2026-02-27

Last updated on: 2026-03-04

Assigner: GitHub, Inc.

Description

Group-Office is an enterprise customer relationship management and groupware tool. Versions prior to 26.0.9, 25.0.87, and 6.8.154 have an authenticated Remote Code Execution vulnerability in the TNEF attachment processing flow. The vulnerable path extracts attacker-controlled files from `winmail.dat` and then invokes `zip` with a shell wildcard (`*`). Because extracted filenames are attacker-controlled, they can be interpreted as `zip` options and lead to arbitrary command execution. Versions 26.0.9, 25.0.87, and 6.8.154 fix the issue.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-02-27

Last Modified

2026-03-04

Generated

2026-07-06

AI Q&A

2026-02-27

EPSS Evaluated

2026-07-05

NVD

CVE-2026-27947

EUVD

EUVD-2026-9060

Affected Vendors & Products

Vendor	Product	Version / Range
intermesh	group-office	to 6.8.154 (exc)
intermesh	group-office	From 25.0.1 (inc) to 25.0.87 (exc)
intermesh	group-office	From 26.0.1 (inc) to 26.0.9 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-88	The product constructs a string for a command to be executed by a separate component in another control sphere, but it does not properly delimit the intended arguments, options, or switches within that command string.
CWE-434	The product allows the upload or transfer of dangerous file types that are automatically processed within its environment.

Attack-Flow Graph

Executive Summary

This vulnerability exists in Group-Office, an enterprise customer relationship management and groupware tool, in versions prior to 26.0.9, 25.0.87, and 6.8.154. It is an authenticated Remote Code Execution (RCE) vulnerability occurring in the TNEF attachment processing flow. Specifically, the vulnerable code extracts attacker-controlled files from a winmail.dat attachment and then runs the zip command with a shell wildcard (*). Because the extracted filenames are controlled by the attacker, they can be interpreted as options to the zip command, which allows the attacker to execute arbitrary commands on the system.

Impact Analysis

This vulnerability can lead to remote code execution on the affected system by an authenticated attacker. This means an attacker who can authenticate to the Group-Office application can execute arbitrary commands on the server, potentially leading to full system compromise, data theft, data loss, or disruption of services.

Compliance Impact

I don't know

Detection Guidance

I don't know

Mitigation Strategies

To mitigate this vulnerability, you should upgrade Group-Office to version 26.0.9, 25.0.87, or 6.8.154 or later, as these versions contain the fix for the authenticated Remote Code Execution vulnerability in the TNEF attachment processing flow.

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