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CVE-2026-19621

6.5 medium SSVC exploitation: none Analyzed
NVD · CVE.org

Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to strip action integration secrets from post payloads before broadcasting post-deletion web socket events and returning thread API responses, which allows an authenticated channel member to obtain server-side webhook URLs and authentication context from interactive-message posts via the post_deleted websocket event or the threads REST API.. Mattermost Advisory ID: MMSA-2026-00766

Fix

Patch, vendor advisory and mitigation references on NVD 1

Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.

Change history 4

  1. Cpes+2 CPE criteria (now 2)NVD modified 2026-10-27 20:59
  2. StatusUndergoing Analysis → AnalyzedNVD modified 2026-10-27 20:59
  3. StatusReceived → Undergoing AnalysisNVD modified 2026-10-16 19:23
  4. First seenCVSS 6.5NVD modified 2026-10-16 08:17

Affected (CPE criteria) 2

  • cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
  • cpe:2.3:a:mattermost:mattermost_server:11.10.0:*:*:*:*:*:*:*

References 1