CVE-2026-19541

EUVD-2026-102805
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
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
MattermostCNA
6.5 MEDIUM
NETWORK
LOW
LOW
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: 11.67%
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
mattermostmattermost
11.9.0 ≤
𝑥
≤ 11.9.1
CNA
mattermostmattermost
11.8.0 ≤
𝑥
≤ 11.8.5
CNA
mattermostmattermost
11.7.0 ≤
𝑥
≤ 11.7.10
CNA
mattermostmattermost
11.10.0 ≤
𝑥
≤ 11.10.1
CNA