CVE-2025-49810Network attack vector

Thread disclosure via stale AI-post authorization

Published Aug 21, 2025 · Updated Aug 21, 2025

Incorrect authorization in Mattermost 10.5.0 through 10.5.8 allows remote authenticated users to read inaccessible threads via AI posts. The AI-post thread-reading path fails to revalidate channel access when the thread is accessed; public records do not name the responsible function or endpoint. A valid account and user interaction are required, and the bounded consequence is disclosure of thread content the account can no longer access.

CVSS severity3.5
Low
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect authorization in Mattermost 10.5.0 through 10.5.8 allows remote authenticated users to read inaccessible threads via AI posts. The AI-post thread-reading path fails to revalidate channel access when the thread is accessed; public records do not name the responsible function or endpoint. A valid account and user interaction are required, and the bounded consequence is disclosure of thread content the account can no longer access.

The record

CVE
CVE-2025-49810
Published
Aug 21, 2025
Updated
Aug 21, 2025
Vendor
Mattermost
Product
Mattermost
Classifications
CWE-863, T1213
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 21, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 21, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

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

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Mattermost · Mattermostversion=10.5.0 <=10.5.8

Published CVSS scores

3.5Mattermost, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:R/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-863Incorrect Authorization
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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