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).
Metrics
Affected Vendors & Products
References
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| https://mattermost.com/security-updates |
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History
Fri, 28 Nov 2025 15:15:00 +0000
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Fri, 28 Nov 2025 09:00:00 +0000
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Mattermost mattermost |
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Mattermost
Mattermost mattermost |
Thu, 27 Nov 2025 18:00:00 +0000
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| 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). | |
| Title | Account Takeover via Code Exchange Endpoint | |
| Weaknesses | CWE-303 | |
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| Metrics |
cvssV3_1
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Status: PUBLISHED
Assigner: Mattermost
Published: 2025-11-27T17:47:04.944Z
Updated: 2025-11-28T14:52:19.096Z
Reserved: 2025-10-28T16:54:12.491Z
Link: CVE-2025-12421
Updated: 2025-11-28T14:52:13.431Z
Status : Undergoing Analysis
Published: 2025-11-27T18:15:46.223
Modified: 2025-11-28T23:11:55.537
Link: CVE-2025-12421
No data.
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