cve.bz

CVE-2026-0999

4.3 mediumEPSS 0.2%

Medium (4.3) in mattermost mattermost server. EPSS 0.2% chance of exploitation in the next 30 days. Fixed in github.com/mattermost/mattermost/server/v8 8.0.0-20251212052346-61651b0df7ea.

Mattermost versions 11.1.x <= 11.1.2, 10.11.x <= 10.11.9, 11.2.x <= 11.2.1 fail to properly validate login method restrictions which allows an authenticated user to bypass SSO-only login requirements via userID-based authentication. Mattermost Advisory ID: MMSA-2025-00548

Severity

CVSS 3.1

4.3 medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
EPSS
0.2% chance of exploitation in the next 30 days; higher than 9% of CVEs (scores of 2026-10-31)
CWE
CWE-303
Published
Modified
Record from
the NVD, synced

Affected

Packages (OSV)

AdvisoryEcosystemPackageAffectedFixed in
GHSA-3c9r-7f29-qp32Gogithub.com/mattermost/mattermost/server/v8<8.0.0-20251212052346-61651b0df7ea8.0.0-20251212052346-61651b0df7ea
GHSA-3c9r-7f29-qp32Gogithub.com/mattermost/mattermost-server>=11.1.0no fix published
GHSA-3c9r-7f29-qp32Gogithub.com/mattermost/mattermost-server>=10.11.0no fix published
GHSA-3c9r-7f29-qp32Gogithub.com/mattermost/mattermost-server>=11.2.0no fix published
GHSA-3c9r-7f29-qp32Gogithub.com/mattermost/mattermost-server<5.3.2-0.20251212052346-61651b0df7ea5.3.2-0.20251212052346-61651b0df7ea
GO-2026-4520Gogithub.com/mattermost/mattermost-serverall versionsno fix published
GO-2026-4520Gogithub.com/mattermost/mattermost-server>=10.11.0+incompatibleno fix published
GO-2026-4520Gogithub.com/mattermost/mattermost-server>=11.1.0+incompatibleno fix published
GO-2026-4520Gogithub.com/mattermost/mattermost-server>=11.2.0+incompatibleno fix published
GO-2026-4520Gogithub.com/mattermost/mattermost-server/v5all versionsno fix published
GO-2026-4520Gogithub.com/mattermost/mattermost-server/v6all versionsno fix published
GO-2026-4520Gogithub.com/mattermost/mattermost/server/v8<8.0.0-20251212052346-61651b0df7ea8.0.0-20251212052346-61651b0df7ea

References

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