4.3

CVE-2026-16049

_GitLab Plugin allows cross-channel post injection and phishing via missing channel permission checks in issue API endpoints_

Mattermost Plugins versions <=11.8 10.20.11 11.5.7.0 _The Mattermost GitLab plugin fails to verify channel permissions when processing API requests with a caller-supplied_ {{post_id}}_, and fails to validate the_ {{web_url}} _parameter against the configured GitLab instance, which allows an authenticated attacker to inject bot-authored messages containing arbitrary URLs into channels they do not have access to via the_ {{createIssue}} _and_ {{attachCommentToIssue}} _API endpoints._ Mattermost Advisory ID: MMSA-2026-00673
Daten sind bereitgestellt durch das CVE Programm von einer CVE Numbering Authority (CNA) (Unstrukturiert).
HerstellerMattermost
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Produkt Mattermost
Default Statusunaffected
Version <= 10.20.11
Version 0
Status affected
Version <= 11.5.7
Version 0
Status affected
Version 11.9.0
Status unaffected
Version 10.11.21
Status unaffected
Version 11.7.6
Status unaffected
VulnDex Vulnerability Enrichment
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Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.22% 0.125
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
responsibledisclosure@mattermost.com 4.3 2.8 1.4
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
CWE-862 Missing Authorization

The product does not perform an authorization check when an actor attempts to access a resource or perform an action.

https://mattermost.com/security-updates