{"id":"EUVD-2025-199833","enisaUuid":"02c15e3c-0cba-3798-926a-a4503e82120c","description":"Mattermost versions 11.0.x \u003c\u003d 11.0.2, 10.12.x \u003c\u003d 10.12.1, 10.11.x \u003c\u003d 10.11.4, 10.5.x \u003c\u003d 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).","datePublished":"Nov 27, 2025, 5:47:04 PM","dateUpdated":"Feb 26, 2026, 4:07:25 PM","baseScore":9.9,"baseScoreVersion":"3.1","baseScoreVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","references":"https://mattermost.com/security-updates\n","aliases":"CVE-2025-12421\nGHSA-mp6x-97xj-9x62\n","assigner":"Mattermost","epss":0.45,"enisaIdProduct":[{"id":"225526e1-9dba-3b55-945f-91b2ca8a2c95","product":{"name":"Mattermost","vendor":{"name":"Mattermost"}},"product_version":"10.12.0 ≤10.12.1"},{"id":"2407ba21-f913-338c-8bc8-ac13338c1c19","product":{"name":"Mattermost","vendor":{"name":"Mattermost"}},"product_version":"10.5.0 ≤10.5.12"},{"id":"2f3a1349-dcfe-3faf-9879-b0c75d577af9","product":{"name":"Mattermost","vendor":{"name":"Mattermost"}},"product_version":"11.0.0 ≤11.0.2"},{"id":"ab26c78a-c4b9-3bcb-8099-1ebe12d77fcf","product":{"name":"Mattermost","vendor":{"name":"Mattermost"}},"product_version":"10.11.0 ≤10.11.4"}],"enisaIdVendor":[{"id":"78368104-32dd-3df5-af22-3c602aa256fa","vendor":{"name":"Mattermost"}}],"enisaIdVulnerability":[{"id":"5ae304a2-3907-3cdd-8503-b6255f2ae290","vulnerability":{"id":"CVE-2025-12421","description":"Mattermost versions 11.0.x \u003c\u003d 11.0.2, 10.12.x \u003c\u003d 10.12.1, 10.11.x \u003c\u003d 10.11.4, 10.5.x \u003c\u003d 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).","datePublished":"Nov 27, 2025, 5:47:04 PM","dateUpdated":"Feb 26, 2026, 4:07:25 PM","status":"PUBLISHED","baseScore":9.9,"baseScoreVersion":"3.1","baseScoreVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","references":"https://mattermost.com/security-updates\n","enisa_id":"EUVD-2025-199833\n","assigner":"Mattermost","epss":0.45,"dataProcessed":"Nov 6, 2026, 7:17:28 AM","vulnerabilityProduct":[{"id":"0ca5961d-2469-375e-9473-e6a306cf71b3","product":{"name":"Mattermost","vendor":{"name":"Mattermost"}},"product_version":"10.12.0 ≤10.12.1"},{"id":"5910f2d4-6469-3ac6-bc0a-13d04ed64399","product":{"name":"Mattermost","vendor":{"name":"Mattermost"}},"product_version":"11.0.0 ≤11.0.2"},{"id":"7253c3e0-a7c4-356f-827e-37a467abecf2","product":{"name":"Mattermost","vendor":{"name":"Mattermost"}},"product_version":"10.11.0 ≤10.11.4"},{"id":"95c2ad27-14ca-3dba-bd7c-ed4655b3ad62","product":{"name":"Mattermost","vendor":{"name":"Mattermost"}},"product_version":"10.5.0 ≤10.5.12"}],"vulnerabilityVendor":[{"id":"d5599a07-76e6-3740-8796-820aefbd1e45","vendor":{"name":"Mattermost"}}]}},{"id":"fe5ab91c-6adf-3b2a-97ce-b911a81d6430","vulnerability":{"id":"GHSA-mp6x-97xj-9x62","description":"Mattermost fails to to verify the token used during code exchange","datePublished":"Nov 27, 2025, 6:30:26 PM","dateUpdated":"Dec 1, 2025, 11:57:10 PM","baseScore":0.0,"references":"https://nvd.nist.gov/vuln/detail/CVE-2025-12421\nhttps://github.com/mattermost/mattermost/commit/5072bbf689a46b3b97b2373f26149f5891396e6b\nhttps://github.com/mattermost/mattermost/commit/acda1fb5dd46a2f46c76ae67012423c760525eaa\nhttps://github.com/mattermost/mattermost/commit/f361e7d75a7ab9df5a2106e1ceb919b94b55e41d\nhttps://github.com/mattermost/mattermost/commit/feb598ed2b7ac3cb78a253b032ad7e4628b0de00\nhttps://github.com/mattermost/mattermost\nhttps://mattermost.com/security-updates\n","enisa_id":"EUVD-2025-199833\n","aliases":"GHSA-mp6x-97xj-9x62\nCVE-2025-12421\n","epss":0.0,"dataProcessed":"Nov 1, 2026, 1:56:19 AM","vulnerabilityProduct":[],"vulnerabilityVendor":[]}}],"enisaIdAdvisory":[{"id":"0d194bc3-be23-3b43-af0f-fe88a6a4d993","advisory":{"id":"NCSC-2025-0378","description":"Kwetsbaarheden verholpen in Mattermost","datePublished":"Nov 28, 2025, 9:53:42 AM","dateUpdated":"Nov 28, 2025, 9:53:42 AM","baseScore":0.0,"references":"","aliases":"CVE-2025-12421\nCVE-2025-12419\n","source":{"id":19,"name":"csaf_ncscnl"},"advisoryProduct":[{"id":"7030d270-0a5e-30f6-b7f9-4369897a2e0c","product":{"name":"vers:unknown/*","vendor":{"name":"Cisco"}}},{"id":"8416951e-3aeb-3953-b264-dd3bfdb559f9","product":{"name":"Mattermost","vendor":{"name":"Mattermost"}}}]}}]}