CVE-2025-13870Network attack vector

Cross-board file disclosure via missing permission checks

Published Dec 2, 2025 · Updated Dec 2, 2025

Authorization bypass in Mattermost Boards 10.5.0 through 10.5.12 and 10.11.0 through 10.11.4 lets remote authenticated users read inaccessible files. The Boards file-access and block-subscription paths accept references to other boards without verifying that the requesting user has permission for the referenced board. A valid account and references to another board's files or blocks are required; the reported impact is file disclosure and unauthorized block subscriptions.

CVSS severity3.1
Low
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authorization bypass in Mattermost Boards 10.5.0 through 10.5.12 and 10.11.0 through 10.11.4 lets remote authenticated users read inaccessible files. The Boards file-access and block-subscription paths accept references to other boards without verifying that the requesting user has permission for the referenced board. A valid account and references to another board's files or blocks are required; the reported impact is file disclosure and unauthorized block subscriptions.

The record

CVE
CVE-2025-13870
Published
Dec 2, 2025
Updated
Dec 2, 2025
Vendor
Mattermost
Product
Mattermost
Classifications
CWE-306, CWE-284, T1213
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 2, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 2, 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=10.11.0 <=10.11.4
  2. Affected versionversion=10.5.0 <=10.5.12

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Mattermost · Mattermostversion=10.11.0 <=10.11.4; version=10.5.0 <=10.5.12

Published CVSS scores

3.1Mattermost, Inc.CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N
4.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-306Missing Authentication for Critical Function
CWE-284Improper Access Control
T1213Data from Information Repositories

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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