CVE-2026-4053

What it is

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

At a glance

Exploitability

Can be exploited over the network with a low-privilege account. Limited direct impact.

Exploit odds

0.2% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-05-15 19:17 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 10:55 UTC Last updatedMost recent change to the record

Details

Published

2026-05-15 19:17 UTC

Last modified

2026-06-17 10:55 UTC

Exploit probability

0.2% · EPSS, next 30 days

Weakness

CWE-672

Record status

Analyzed

Affected

• Mattermost Server < 10.11.14
• Mattermost Server < 11.5.2

Attack profile CVSS 3.1 · 3.1

Attack vector

Network

Complexity

High

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

Low

Availability

None