Medium severity4.3NVD Advisory· Published May 21, 2026· Updated May 21, 2026
CVE-2026-4055
CVE-2026-4055
Description
Mattermost versions 11.5.x <= 11.5.1 fail to validate team-level run_create permission against the target team when creating a playbook run which allows an authenticated team member to create runs in teams where they lack permission via specifying a different team ID in the run creation API request. Mattermost Advisory ID: MMSA-2026-00629
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
Affected packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
github.com/mattermost/mattermost/server/v8Go | >= 8.0.0-20260304132957-9f2616376582, < 8.0.0-20260320113102-f2b3d1c6a945 | 8.0.0-20260320113102-f2b3d1c6a945 |
Affected products
4>=11.5.0,<=11.5.1+ 2 more
- (no CPE)range: >=11.5.0,<=11.5.1
- cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*range: >=10.11.0,<10.11.17
- (no CPE)range: >=11.5.0, <=11.5.1
- ghsa-coordsRange: >= 8.0.0-20260304132957-9f2616376582, < 8.0.0-20260320113102-f2b3d1c6a945
Patches
Vulnerability mechanics
References
3- github.com/advisories/GHSA-6cfr-wp44-6qmvghsaADVISORY
- mattermost.com/security-updatesnvdVendor AdvisoryWEB
- nvd.nist.gov/vuln/detail/CVE-2026-4055ghsaADVISORY
News mentions
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