CVE-2025-20051

CRITICAL

Mattermost allows reading arbitrary files

Published February 24, 2025Updated February 4, 2026Source: osv

Summary

Mattermost versions 10.4.x <= 10.4.1, 9.11.x <= 9.11.7, 10.3.x <= 10.3.2, 10.2.x <= 10.2.2 fail to properly validate input when patching and duplicating a board, which allows a user to read any arbitrary file on the system via duplicating a specially crafted block in Boards.

Remediation

Upgrade to the fixed version using your package manager.

Update github.com/mattermost/mattermost/server/v8 to 10.3.3 or later

go get github.com/mattermost/mattermost/server/v8@v10.3.3

Update github.com/mattermost/mattermost/server/v8 to 10.4.2 or later

go get github.com/mattermost/mattermost/server/v8@v10.4.2

Update github.com/mattermost/mattermost/server/v8 to 8.0.0-20250122165010-4ed702ccff4e or later

go get github.com/mattermost/mattermost/server/v8@v8.0.0-20250122165010-4ed702ccff4e

Update github.com/mattermost/mattermost/server/v8 to 10.2.3 or later

go get github.com/mattermost/mattermost/server/v8@v10.2.3

Update github.com/mattermost/mattermost/server/v8 to 9.11.8 or later

go get github.com/mattermost/mattermost/server/v8@v9.11.8

After upgrading, run your dependency scanner again to confirm the vulnerability is resolved.

Affected Packages (5)

Package	Ecosystem	Affected	Fixed In
github.com/mattermost/mattermost/server/v8	go	All versions	10.3.3
github.com/mattermost/mattermost/server/v8	go	All versions	10.4.2
github.com/mattermost/mattermost/server/v8	go	All versions	8.0.0-20250122165010-4ed702ccff4e
github.com/mattermost/mattermost/server/v8	go	All versions	10.2.3
github.com/mattermost/mattermost/server/v8	go	All versions	9.11.8

Vulnerability Classification

Common Weakness Enumeration (CWE) identifiers for this vulnerability type.

CWE-22
Path TraversalMITRE

CVSS Score Breakdown

What the CVSS (Common Vulnerability Scoring System) 9.9 score means for each attack dimension.

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Changed

Confidentiality

High

Integrity

High

Availability

High

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

References

Frequently Asked Questions

What is CVE-2025-20051?: Mattermost allows reading arbitrary files This vulnerability has been assigned a severity rating of CRITICAL (CVSS score: 9.9/10).
How do I check if my project is affected by CVE-2025-20051?: CVE-2025-20051 affects github.com/mattermost/mattermost/server/v8. Use GeekWala's free vulnerability scanner to check your dependencies against CVE-2025-20051 and 200,000+ other known vulnerabilities.

Severity & Exploitability

CVSS Score

9.9

Exploitation is straightforward and causes maximum impact. Patch immediately.

Also Known As

GHSA-v469-7wp6-7cvp

GO-2025-3483

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