Cyber Resilience

CVE-2026-22545

Access Control in Mattermost Server 10.11.0 – 10.11.11

Published
16 March 2026
Modified
18 March 2026
Patch / advisory
CVSS Score v3.1 3.1
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N
EPSS Score 0.0015 5th percentile
Risk Priority 15 floored blend · peak EPSS

Summary

CVE-2026-22545 is a low-severity Incorrect Authorization (CWE-863) vulnerability in Mattermost Mattermost Server. Its CVSS base score is 3.1 (Low).

Operationally, exploitation aligns with the MITRE ATT&CK technique Account Manipulation (T1098); ranked at the 5th 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 IA-11 (Re-authentication) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Mattermost versions 10.11.x <= 10.11.10 fail to validate user's authentication method when processing account auth type switch which allows an authenticated attacker to change account password without confirmation via falsely claiming a different auth provider.. Mattermost Advisory ID: MMSA-2026-00583

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1098 Account Manipulation Persistence
Adversaries may manipulate accounts to maintain and/or elevate access to victim systems.
Why these techniques?

Vulnerability enables unauthorized modification of account credentials (password) by bypassing auth method validation.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-8823Same product: Mattermost Mattermost Server
CVE-2026-26230Same product: Mattermost Mattermost Server
CVE-2026-4274Same product: Mattermost Mattermost Server
CVE-2026-6343Same product: Mattermost Mattermost Server
CVE-2026-2462Same product: Mattermost Mattermost Server
CVE-2025-11776Same product: Mattermost Mattermost Server
CVE-2024-9155Same product: Mattermost Mattermost Server
CVE-2026-10106Same product: Mattermost Mattermost Server
CVE-2026-6739Same product: Mattermost Mattermost Server
CVE-2024-42000Same product: Mattermost Mattermost Server

Affected Assets

mattermost
mattermost server
10.11.0 — 10.11.11

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • AC-3 Access Enforcement
  • IA-11 Re-authentication
  • AC-6 Least Privilege
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 auth-type switch operation so an authenticated user cannot falsely claim a different provider to bypass password-change confirmation.

prevent

Requires re-authentication before allowing a password change, preventing the unauthorized auth-type switch from succeeding without current credentials.

prevent

Restricts the ability to modify account authenticators to only the minimal set of privileged operations and roles, limiting abuse of the flawed switch path.

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 mostly match
prevents

Defining, enforcing, and reviewing access authorizations and least privilege directly prevents incorrect 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 consistency between access rights and classification plus formal approval steps ensures that the authorization logic correctly distinguishes between entities that should and should not be granted access.

prevents

Enforcing policy-driven approval and role-change reviews stops incorrect or stale authorization decisions from remaining in effect after job changes or terminations.

prevents

By tying access rights to identity, device, location and classification, the control reduces the likelihood that an authorization decision will be based on an incorrect or bypassed policy.

References