CVE-2025-9081Network attack vector

Authenticated file disclosure via unchecked board UUID

Published Sep 19, 2025 · Updated Sep 19, 2025

Authorization bypass in Mattermost 9.11.0 through 9.11.17 and 10.5.0 through 10.5.8 allows remote authenticated users to read board files. The Boards file download endpoint accepts an attacker-supplied file UUID and returns the file without verifying that its path or block reference belongs to the requested board. Any authenticated account can enumerate UUIDs to retrieve files attached to inaccessible boards; no write or service-interruption impact is reported.

CVSS severity3.1
Low
EPSS probability0.27%
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 9.11.0 through 9.11.17 and 10.5.0 through 10.5.8 allows remote authenticated users to read board files. The Boards file download endpoint accepts an attacker-supplied file UUID and returns the file without verifying that its path or block reference belongs to the requested board. Any authenticated account can enumerate UUIDs to retrieve files attached to inaccessible boards; no write or service-interruption impact is reported.

The record

CVE
CVE-2025-9081
Published
Sep 19, 2025
Updated
Sep 19, 2025
Vendor
Mattermost
Product
Mattermost
Classifications
CWE-639, T1213
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 19, 2025CVE publishedPublication date reported by the CVE source.
  2. Sep 19, 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=10.5.0 <=10.5.8
  2. Affected versionversion=9.11.0 <=9.11.17

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Mattermost · Mattermostversion=10.5.0 <=10.5.8; version=9.11.0 <=9.11.17

Published CVSS scores

6.5NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
3.1Mattermost, Inc.CVSS:3.1/AV:N/AC:H/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 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-639Authorization Bypass Through User-Controlled Key
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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