Description
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
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mattermost | Mattermost | 11.5.0 – ≤ 11.5.1, 10.11.0 – ≤ 10.11.13 | 11.6.0 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 16.0 | govulncheck-vulndb | 0.0.20260723T184607-160000.1.1 | openSUSE-SU-2026:21483-1 |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Go | github.com/mattermost/mattermost-server | >= 11.5.0, < 11.5.2 | 11.5.2 | GHSA-hw87-6jcq-9f8q |
| Go | github.com/mattermost/mattermost-server | >= 0.0.0-20250731163400-5b955468ea1e, < 0.0.0-20260414103857-b21ef302025e | 0.0.0-20260414103857-b21ef302025e | GHSA-hw87-6jcq-9f8q |
| Go | github.com/mattermost/mattermost-server | >= 0.0.0-20250731163400-5b955468ea1e, < 0.0.0-20260414103857-b21ef302025e · >= 11.5.0+incompatible, < 11.5.2+incompatible | 0.0.0-20260414103857-b21ef302025e, 11.5.2+incompatible | GO-2026-5442 |
Advisories 2
- openSUSE-SU-2026:21483-1 Security update for govulncheck-vulndb SUSE / openSUSE Security Updates · Jul 31, 2026
- WID-SEC-2026-1154 Mattermost: Mehrere Schwachstellen ermöglichen nicht spezifizierten Angriff BSI CERT-Bund (WID) · May 18, 2026
References
- MMSA-2026-00631 vendor-advisory