CVE-2026-18560 — Improper order of authorisations in Mattermost GetFile API leads to an authenticated user to determine a post’s quara…

CVE-2026-18560

Improper order of authorisations in Mattermost GetFile API leads to an authenticated user to determine a post’s quarantined status PUBLISHED

Description (CNA)

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 validate user’s permissions before other validations which allows non-content reviewers to infer a post’s flagged status via direct API call.. Mattermost Advisory ID: MMSA-2026-00754

Affected (CNA)

Vendor / product	Versions
Mattermost / Mattermost	affected 11.10.0 through 11.10.0; affected 11.7.0 through 11.7.9; affected 11.9.0 through 11.9.1; affected 11.8.0 through 11.8.5; unaffected 11.11.0; unaffected 11.10.1; unaffected 11.7.10; unaffected 11.9.2; unaffected 11.8.6

CWE

CWE-203

References

https://mattermost.com/security-updates

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.