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.
Metrics
Affected Vendors & Products
No advisories yet.
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
Thu, 17 Sep 2026 19:30:00 +0000
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ssvc
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Thu, 17 Sep 2026 13:30:00 +0000
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| Description | 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. | |
| Title | Sign-in token minted for one resource accepted by another in AshAuthentication | |
| First Time appeared |
Team-alembic
Team-alembic ash Authentication |
|
| Weaknesses | CWE-287 | |
| CPEs | cpe:2.3:a:team-alembic:ash_authentication:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Team-alembic
Team-alembic ash Authentication |
|
| References |
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|
| Metrics |
cvssV4_0
|
Projects
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Status: PUBLISHED
Assigner: EEF
Published:
Updated: 2026-09-17T18:28:47.571Z
Reserved: 2026-09-11T18:30:01.333Z
Link: CVE-2026-80218
Updated: 2026-09-17T18:28:45.145Z
Status : Received
Published: 2026-09-17T14:17:30.743
Modified: 2026-09-17T19:17:03.287
Link: CVE-2026-80218
No data.
OpenCVE Enrichment
No data.