CVE-2024-39361Network attack vector

Channel disruption via user-defined post identifiers

Published Jul 3, 2024 · Updated Aug 2, 2024

Improper access control in the Mattermost CreatePost API allows remote authenticated users to disrupt channel or thread functionality. The API accepts both RemoteId and a caller-supplied post ID instead of rejecting that combination, storing a post under an attacker-chosen identifier. A valid user session and permission to create a post are required; the documented consequence is broken channel or thread behavior, not data disclosure.

CVSS severity3.1
Low
EPSS probability0.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper access control in the Mattermost CreatePost API allows remote authenticated users to disrupt channel or thread functionality. The API accepts both RemoteId and a caller-supplied post ID instead of rejecting that combination, storing a post under an attacker-chosen identifier. A valid user session and permission to create a post are required; the documented consequence is broken channel or thread behavior, not data disclosure.

The record

CVE
CVE-2024-39361
Published
Jul 3, 2024
Updated
Aug 2, 2024
Vendor
Mattermost
Product
Mattermost
Classifications
CWE-284, T1565.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 3, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 2, 2024Record 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=9.5.0 <=9.5.5
  2. Affected versionversion=9.6.0 <=9.6.2
  3. Affected versionversion=9.7.0 <=9.7.4
  4. Affected versionversion=9.8.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Mattermost · Mattermostversion=9.5.0 <=9.5.5; version=9.6.0 <=9.6.2; version=9.7.0 <=9.7.4; version=9.8.0

Published CVSS scores

3.1Mattermost, Inc.CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L
5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L

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-284Improper Access Control
T1565.001Stored Data Manipulation

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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