CVE-2023-6547Network attack vector

Playbook access and modification via stale permissions

Published Dec 12, 2023 · Updated May 12, 2025

Improper access control in Mattermost 8.1.5 and earlier and 9.2.1 and earlier allows remote authenticated users to access and modify playbooks. The playbook access path checks retained playbook permissions but does not revalidate membership in the playbook's owning team. Exploitation requires an account that previously belonged to the team and retained playbook permissions after removal; successful access permits viewing and modification.

CVSS severity3.7
Low
EPSS probability0.32%
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 Mattermost 8.1.5 and earlier and 9.2.1 and earlier allows remote authenticated users to access and modify playbooks. The playbook access path checks retained playbook permissions but does not revalidate membership in the playbook's owning team. Exploitation requires an account that previously belonged to the team and retained playbook permissions after removal; successful access permits viewing and modification.

The record

CVE
CVE-2023-6547
Published
Dec 12, 2023
Updated
May 12, 2025
Vendor
Mattermost
Product
Mattermost
Classifications
CWE-284, T1078
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 12, 2023CVE publishedPublication date reported by the CVE source.
  2. May 12, 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=0 <=8.1.5
  2. Affected versionversion=0 <=9.2.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Mattermost · Mattermostversion=0 <=8.1.5; version=0 <=9.2.1

Published CVSS scores

3.7MattermostCVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:L/A:N
5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/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-284Improper Access Control
T1078Valid Accounts

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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