Attestkeep
Language: English
Sign up

Vulnerabilities / CVE-2025-12421

critical

CVE-2025-12421

Mattermost fails to to verify the token used during code exchange

Published Modified CWE 303
In the Trivy database since at least 24 Oct 2026, 07:11 UTCWhen it arrived before that build is not recorded.

Severity by source

GHSA10.0CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Trivy's own label is CRITICAL. Rated critical by GHSA.

Description

Mattermost versions 11.0.x <= 11.0.2, 10.12.x <= 10.12.1, 10.11.x <= 10.11.4, 10.5.x <= 10.5.12 fail to to verify that the token used during the code exchange originates from the same authentication flow, which allows an authenticated user to perform account takeover via a specially crafted email address used when switching authentication methods and sending a request to the /users/login/sso/code-exchange endpoint. The vulnerability requires ExperimentalEnableAuthenticationTransfer to be enabled (default: enabled) and RequireEmailVerification to be disabled (default: disabled).

Affected packages and fixed versions

SourcePackageFixed in
go::GitHub Security Advisory Gogithub.com/mattermost/mattermost-server, github.com/mattermost/mattermost/server/v811.0.3, 10.12.2, 10.11.5, 10.5.13 and 1 more
Show all 2 entries from 1 source
SourcePackageFixed in
go::GitHub Security Advisory Gogithub.com/mattermost/mattermost-server11.0.3, 10.12.2, 10.11.5, 10.5.13
go::GitHub Security Advisory Gogithub.com/mattermost/mattermost/server/v88.0.0-20251022210333-acda1fb5dd46

References

Vulnerability data compiled from the Trivy vulnerability database (trivy-db, Aqua Security, Apache License 2.0), which aggregates third-party advisories. CVE records are published by The MITRE Corporation under the CVE Terms of Use; CVE is a trademark of MITRE. This product uses data from the NVD API but is not endorsed or certified by the NVD. Severity, titles and advisory data from the GitHub Advisory Database (CC BY 4.0), Red Hat security data (CC BY 4.0) and the other sources linked on each entry. Entries may be summarised or re-formatted; the linked original is the authoritative record.