Cyber Resilience

CVE-2025-41443

Access Control in Mattermost Server 10.5.0 – 10.5.11

Published
16 October 2025
Modified
29 October 2025
Patch / advisory
CVSS Score v3.1 4.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
EPSS Score 0.0028 21th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2025-41443 is a medium-severity Missing Authorization (CWE-862) vulnerability in Mattermost Mattermost Server. Its CVSS base score is 4.3 (Medium).

Operationally, ranked at the 21th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and AC-6 (Least Privilege) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Mattermost versions 10.5.x <= 10.5.12, 10.11.x <= 10.11.2 fail to properly validate guest user permissions when accessing channel information which allows guest users to discover active public channels and their metadata via the `/api/v4/teams/{team_id}/channels/ids` endpoint

CWE(s)

Related Threats

CVEs Like This One

CVE-2025-9076Same product: Mattermost Mattermost Server
CVE-2024-50052Same product: Mattermost Mattermost Server
CVE-2025-58073Same product: Mattermost Mattermost Server
CVE-2023-1774Same product: Mattermost Mattermost Server
CVE-2023-5331Same product: Mattermost Mattermost Server
CVE-2025-58075Same product: Mattermost Mattermost Server
CVE-2025-41410Same product: Mattermost Mattermost Server
CVE-2023-3587Same product: Mattermost Mattermost Server
CVE-2024-23493Same product: Mattermost Mattermost Server
CVE-2025-54458Same vendor: Mattermost

Affected Assets

mattermost
mattermost server
10.5.0 — 10.5.11 · 10.11.0 — 10.11.3

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • AC-3 Access Enforcement
  • AC-6 Least Privilege
  • AC-4 Information Flow Enforcement
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 5 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly enforces authorization checks on the /api/v4/teams/{team_id}/channels/ids endpoint so guest accounts cannot retrieve channel metadata they are not permitted to see.

prevent

Limits guest accounts to the minimum set of privileges required, preventing the unauthorized channel discovery that occurs when guest permissions are not properly scoped.

prevent

Enforces information-flow rules that block guest users from receiving channel metadata they are not authorized to obtain.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.AA-05 full match
prevents

Explicitly requires defining, enforcing, and reviewing authorizations and least privilege, directly preventing missing authorization checks.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Requiring authentication and credentials before any access occurs eliminates the absence of authorization checks that would otherwise allow an unauthenticated actor to reach protected resources.

prevents

Requiring formal authorization of every access request before rights are granted ensures that checks for required permissions are performed, preventing missing authorization checks from being introduced.

prevents

Mandatory authorization checks and central records of granted rights ensure that every access attempt is preceded by an explicit decision rather than relying on missing checks.

mitigates

Segregating the approval of access rights from their implementation provides an independent check that reduces the impact of missing authorization checks in the resulting system configuration.

detects

By requiring competent outsiders to verify that every function enforces the need-to-know principle, the control lowers the likelihood that missing authorization checks persist undetected.

prevents

Defining authorization responsibilities and reviewing risk-treatment progress throughout the project lifecycle catches missing authorization checks before the system is deployed.

References