# Mattermost Server Patches Unspecified Flaw

Published: 2026-10-23 · Severity: elevated · Sectors: Technology · Not tied to an actor or CVE
Canonical: https://vorant.io/reports/726600a7-b7b4-5553-bb73-051b7424d486/mattermost-server-patches-unspecified-flaw
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> CERT-FR advises patching a vulnerability of unspecified impact in Mattermost Server versions 11.7.x before 11.7.14.

Source: cert.cyber.gouv.fr — https://www.cert.cyber.gouv.fr/avis/CERTFR-2026-AVI-1368

## What to check

- Applies to: Not tied to a specific actor, malware or CVE, only to the sectors it covers, so it may be general reporting. Check the source before acting on it. Whether it concerns you is not assessed.

CERT-FR issued an advisory regarding a vulnerability in Mattermost Server affecting versions 11.7.x prior to 11.7.14. The vendor has not disclosed the specific nature or risk of the flaw, referencing it only via security bulletin MMSA-2026-00708 published on 22 October 2026. No technical details on exploitation method, impact, or whether the vulnerability is being actively exploited in the wild are provided in this advisory.

Defenders running affected Mattermost Server versions should consult the vendor's official security bulletin for patch details and apply the update to version 11.7.14 or later as soon as possible. Given the lack of specifics, organizations should treat this as a standard patch-management action and monitor for any follow-up disclosure from Mattermost regarding the nature of the vulnerability.

Source reporting: https://www.cert.cyber.gouv.fr/avis/CERTFR-2026-AVI-1368

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