CVE-2025-58075Network attack vector

Restricted-team access via unvalidated RelayState team ID

Published Oct 16, 2025 · Updated Oct 16, 2025

Missing authorization in affected Mattermost servers allows remote authenticated users to join any team through a manipulated SAML RelayState. The external-authentication completion paths trusted a team ID carried in RelayState and added the user directly instead of preserving and validating the original invite token or invite ID. A low-privileged account completing external authentication can substitute a target team identifier and bypass team-joining restrictions, gaining membership and the access available to that team.

CVSS severity8.1
High
EPSS probability0.34%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Missing authorization in affected Mattermost servers allows remote authenticated users to join any team through a manipulated SAML RelayState. The external-authentication completion paths trusted a team ID carried in RelayState and added the user directly instead of preserving and validating the original invite token or invite ID. A low-privileged account completing external authentication can substitute a target team identifier and bypass team-joining restrictions, gaining membership and the access available to that team.

The record

CVE
CVE-2025-58075
Published
Oct 16, 2025
Updated
Oct 16, 2025
Vendor
Mattermost
Product
Mattermost
Classifications
CWE-862, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 16, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 16, 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=10.10.0 <=10.10.2
  2. Affected versionversion=10.11.0 <=10.11.1
  3. Affected versionversion=10.5.0 <=10.5.10

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Mattermost · Mattermostversion=10.10.0 <=10.10.2; version=10.11.0 <=10.11.1; version=10.5.0 <=10.5.10

Published CVSS scores

8.1MattermostCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/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-862Missing Authorization
T1190Exploit Public-Facing Application

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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