Vulnerability · 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…
Published May 15, 2026 · catalog updated Jun 17, 2026 · mattermost server
Last checked Oct 25, 2026. A connected source was read within the last 7 days.
Check if you run it
No confirmed exploitation is on record for CVE-2026-4053. EPSS is 0.17%. Act only if a listed version of mattermost server is installed.
Gaps on this record
- No version range is stored. A customer cannot check an installed version against this record.
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
Same product and reporting
- CVE-2026-86348 · Medium
- CVE-2026-4915 · Medium
- CVE-2026-28735 · Medium
- CVE-2026-5755 · Medium
- CVE-2026-5740 · High
- Severity
- Medium4.3
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 0.17%
- Remediation
- Advisory link
- Affected products
- cpe mattermost/mattermost server
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
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- cpe mattermost/mattermost serverversion unspecified
How to fix CVE-2026-4053
No stored fix
No vendor fix text is stored. Use the linked advisory before you change production.
Version check
No version range is stored, so an installed version cannot be checked on this page.
Advisory
Open the cve_org record and follow its fix.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2026-4053. EPSS is 0.17%. Act only if a listed version of mattermost server is installed.
Which versions are affected?
Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
CWE-672. EPSS 0.17%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
May 15, 2026 · NIST NVD
Detected
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
Jun 17, 2026 · NIST NVD
Updated
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
Sources
- CVE.orgVulnerability recordCVE-2026-4053
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2026-4053
30-day exploitation probability 0.17%
first.org - NIST NVDVulnerability recordCVE-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
nvd.nist.gov
References
Freshness
Last verified in this catalog Oct 25, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.
- FIRST EPSSOct 25, 2026
- NIST NVDOct 20, 2026
- CVE.orgOct 16, 2026