CVE-2026-19541
mediumMattermost 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 require re-entry of the stored client secret when validat…
Vendor / product: Mattermost — mattermost server
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 require re-entry of the stored client secret when validating an outgoing OAuth connection, which allows an authenticated user with permission to manage outgoing OAuth connections to obtain the secret via pointing the token URL at an attacker-controlled endpoint and triggering validation.. Mattermost Advisory ID: MMSA-2026-00761
CVSS
6.5
6.5 (CVSS v3.1)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N Severity source: NVD CVSS v3.1 (responsibledisclosure@mattermost.com)
Timeline (UTC)
Published: 2026-10-16 07:17
Modified: 2026-10-29 18:08
NVD status: Analyzed
Last synced 5 days ago
Verified against the source API 2026-10-30 08:34 UTC
Exploitation
Not listed in CISA KEV (as of last catalog sync)
Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).
Affected products
mattermost / mattermost_server ≥11.7.0 <11.7.11, ≥11.8.0 <11.8.6, ≥11.9.0 <11.9.2, ≥11.10.0 <11.10.2
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
Vendor advisory: https://mattermost.com/security-updates
References
- https://mattermost.com/security-updates responsibledisclosure@mattermost.com
Data sources
NVD CVE API 2.0 — fetched 2026-10-30 08:34 UTC · record ↗