Cyber Resilience

CVE-2026-4053

Mattermost Server 10.11.0 – 10.11.14

Published
15 May 2026
Modified
17 June 2026
Patch / advisory
View advisory
CVSS Score v3.1 3.1
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N
EPSS Score 0.0016 6th percentile
Risk Priority 26 floored blend · peak EPSS

Summary

CVE-2026-4053 is a low-severity Operation on a Resource after Expiration or Release (CWE-672) vulnerability in Mattermost Mattermost Server. Its CVSS base score is 3.1 (Low).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 6th 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-5 (Authenticator Management) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13 fail to enforce the PostEditTimeLimit on non-message post fields which allows an authenticated user to modify post file attachments, props, and pin status after the edit window has expired via the post…

more

patch and update API endpoints.. Mattermost Advisory ID: MMSA-2026-00631

CWE(s)
CWE-672

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-1629Same product: Mattermost Mattermost Server
CVE-2026-2454Same product: Mattermost Mattermost Server
CVE-2025-12689Same product: Mattermost Mattermost Server
CVE-2026-25783Same product: Mattermost Mattermost Server
CVE-2025-20033Same product: Mattermost Mattermost Server
CVE-2025-20088Same product: Mattermost Mattermost Server
CVE-2024-54083Same product: Mattermost Mattermost Server
CVE-2025-13352Same product: Mattermost Mattermost Server
CVE-2025-41395Same product: Mattermost Mattermost Server
CVE-2025-20086Same product: Mattermost Mattermost Server

Affected Assets

mattermost
mattermost server
10.11.0 — 10.11.14 · 11.5.0 — 11.5.2

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 1 hardening rule · 1 OS baseline
Validate
Prove the fix (OWASP ASVS)

—

Mitigating Controls (NIST 800-53 r5) AI

AC-3 Access Enforcement good match

Access enforcement applies current authorizations to every request, directly blocking operations once a resource has been revoked or released.

IA-5 Authenticator Management good match

Authenticator management mandates revocation and replacement procedures that render expired credentials unusable.

AC-2 Account Management partial match

Account lifecycle management includes explicit revocation and disabling steps that stop subsequent operations on released accounts or identifiers.

IA-4 Identifier Management partial match

Identifier management requires deallocation and reuse controls that prevent continued use of released identifiers.

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

Enforcing managed authorizations and revocations directly prevents post-release operations on credentials or entitlements.

PR.PS-06 mostly match
prevents

Secure development practices eliminate the root coding flaw that permits use-after-release.

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.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing can detect use-after-release but does not prevent it at runtime.

A.8.10 Information deletion partial match
degrades

Enforces timely deletion of resources so they cannot be used after release.

A.8.28 Secure coding partial match
prevents

Secure-coding rules require checks that prevent operations on freed or expired objects.

A.8.32 Change management partial match
prevents

Change-management processes can introduce or remove resource-lifetime controls.

References