CVE-2026-96259 — Mattermost server-side request forgery via OAuth endpoints configurable by a System Administrator

CVE-2026-96259

Mattermost server-side request forgery via OAuth endpoints configurable by a System Administrator PUBLISHED

Description (CNA)

Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to apply the internal-connection filter to OAuth endpoint requests, which allows a System Administrator to make the server issue requests to internal network addresses and read the responses via the configured OAuth token and userinfo endpoints.. Mattermost Advisory ID: MMSA-2026-00776

Affected (CNA)

Vendor / product	Versions
Mattermost / Mattermost	affected 11.9.0 through 11.9.1; affected 11.8.0 through 11.8.5; affected 11.7.0 through 11.7.10; affected 11.10.0 through 11.10.1; unaffected 11.11.0; unaffected 11.9.2; unaffected 11.8.6; unaffected 11.7.11; unaffected 11.10.2

CWE

CWE-918

References

https://mattermost.com/security-updates

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.