What is CVE-2026-4053?

CVE-2026-4053 is a low-severity vulnerability in Mattermost, classified under Operation on a Resource after Expiration or Release. CVSS score: 3.1/10. Published 2026-05-15.

How severe is CVE-2026-4053?

Low severity. CVSS v3 base score is 3.1 out of 10.

Vulnerability in Mattermost

CVE-2026-4053

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

EPSS: 0.002 (5.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 3.1 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N.

Affected products

Mattermost — versions 11.5.0, 10.11.0, 11.6.0
Mattermost Mattermost_server

Weakness classification (CWE)

CWE-672 — Operation on a Resource after Expiration or Release

References

responsibledisclosure@mattermost.com (vendor-advisory, Vendor Advisory)

Frequently asked questions

What is CVE-2026-4053?: CVE-2026-4053 is a low-severity vulnerability in Mattermost, classified under Operation on a Resource after Expiration or Release. CVSS score: 3.1/10. Published 2026-05-15.
How severe is CVE-2026-4053?: Low severity. CVSS v3 base score is 3.1 out of 10.