CVE-2025-20051Network attack vector

Authenticated file read via unvalidated block identifiers

Published Feb 24, 2025 · Updated Feb 24, 2025

Path traversal in affected Mattermost Boards releases allows remote authenticated users to read arbitrary server files through board duplication. The duplication path trusts a crafted block's fileId or attachmentId and passes it into file-copy handling without validating path characters. A valid account with board-duplication access is required, and the resulting copy discloses files readable by the server process.

CVSS severity9.9
Critical
EPSS probability0.60%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Path traversal in affected Mattermost Boards releases allows remote authenticated users to read arbitrary server files through board duplication. The duplication path trusts a crafted block's fileId or attachmentId and passes it into file-copy handling without validating path characters. A valid account with board-duplication access is required, and the resulting copy discloses files readable by the server process.

The record

CVE
CVE-2025-20051
Published
Feb 24, 2025
Updated
Feb 24, 2025
Vendor
Mattermost
Product
Mattermost
Classifications
CWE-22, T1005
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 24, 2025CVE publishedPublication date reported by the CVE source.
  2. Feb 24, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=10.2.0 <=10.2.2
  2. Affected versionversion=10.3.0 <=10.3.2
  3. Affected versionversion=10.4.0 <=10.4.1
  4. Affected versionversion=9.11.0 <=9.11.7

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Mattermost · Mattermostversion=10.2.0 <=10.2.2; version=10.3.0 <=10.3.2; version=10.4.0 <=10.4.1; version=9.11.0 <=9.11.7

Published CVSS scores

9.9Mattermost, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
T1005Data from Local System

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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