CVE-2026-10103 Affecting mattermost-10.11 package, versions <10.11.20-r0
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-MINIMOSLATEST-MATTERMOST1011-17973276
- published15 Jul 2026
- disclosed13 Jul 2026
Introduced: 13 Jul 2026
CVE-2026-10103 (opens in a new tab)How to fix?
Upgrade Minimos:latest mattermost-10.11 to version 10.11.20-r0 or higher.
NVD Description
Note: Versions mentioned in the description apply only to the upstream mattermost-10.11 package and not the mattermost-10.11 package as distributed by Minimos.
See How to fix? for Minimos:latest relevant fixed versions and status.
Mattermost versions 11.7.x <= 11.7.2, 11.6.x <= 11.6.4, 10.11.x <= 10.11.19 fail to verify post ownership in the shared channel inbound sync handler, which allows an authenticated remote cluster to modify or delete posts authored by local users or other remotes via crafted sync messages referencing arbitrary post IDs in channels shared with that remote.. Mattermost Advisory ID: MMSA-2026-00689