CVE-2026-80218

published 2026-09-17

CVE-2026-80218: Improper Authentication vulnerability in team-alembic AshAuthentication allows an attacker holding a sign-in token for one authenticated resource to be signed…

Priority P3 52 high 7.6 CVSS 4.0

AV N AC L AT P PR L UI N VC H VI H VA N SC N SI N SA N E X CR X IR X AR X MAV X MAC X MAT X MPR X MUI X MVC X MVI X MVA X MSC X MSI X MSA X S X AU X R X V X RE X U X

Improper Authentication vulnerability in team-alembic AshAuthentication allows an attacker holding a sign-in token for one authenticated resource to be signed in as a user of a different resource.

AshAuthentication.Strategy.Password.SignInWithTokenPreparation.extract_primary_keys_from_subject/2 parses the JWT sub claim (for example user?id=1) with URI.parse/1 and keeps only its query string, discarding the path segment that names the subject the token was issued for. Nothing else restores that binding: AshAuthentication.Jwt.verify/3 checks the signature, exp, nbf, jti and the library-version claims, the purpose check only requires sign_in, and the remaining comparison is over primary-key field names, which are identical across resources. The WebAuthn sign-in and remember-me preparations carry copies of the same helper and drop the path in the same way. The magic link sign-in path pins the subject name against the resource and is not affected.

This issue affects ash_authentication: from 3.10.5 before 4.15.0 and from 5.0.0-rc.0 before 5.0.0-rc.14.

Affected

3 ranges

Vendor	Product	Version range	Fixed in
team-alembic	ash_authentication	>= 3.10.5 < 4.15.0	4.15.0
team-alembic	ash_authentication	>= 5.0.0-rc.0 < 5.0.0-rc.14	5.0.0-rc.14
team-alembic	ash_authentication	>= eca8cadea0f1595ed2c10a0c177b1da9aa9e5269 < *	*

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CWE-287