CVE-2026-86533

CRITICAL CVSS 4.0: 9.1 EPSS 0.65%
Updated Sep 18, 2026
Team-Alembic
Parameter Value
CVSS 9.1 (CRITICAL)
Affected Versions 2.10.0 — 5.0.0-rc.14
Fixed In 4.15.0
Type CWE-613
Vendor Team-Alembic
Public PoC No

Insufficient Session Expiration vulnerability in team-alembic AshAuthentication and AshAuthentication Phoenix allows a revoked session to remain fully authenticated. A resource configured with session_identifier :jti and require_token_presence_for_authentication? disabled stores its session value as <jti>:<subject>. The jti is there so that signing out can revoke that one session.

Neither reader consults it: AshAuthentication.Plug.Helpers.authenticate_resource_from_session/4 and AshAuthentication.Phoenix.LiveSession.on_mount/4 both split the value with split_identifier/2, discard the jti and pass the bare subject to AshAuthentication.subject_to_user/3, which reloads the record. The token-presence branch of each function does check its token, calling AshAuthentication.TokenResource.Actions.get_token/3 with the jti and the purpose user. Because the revocation record is never read, neither its revoked state nor its expiry constrains the session, so a session captured before sign-out keeps working.

This issue affects ash_authentication: from 4.9.1 before 4.15.0 and from 5.0.0-rc.0 before 5.0.0-rc.14; ash_authentication_phoenix: from 2.10.0 before 2.17.4 and from 3.0.0-rc.0 before 3.0.0-rc.11.

Attack Parameters

Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
Present
Additional conditions required
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed

Impact Assessment

Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
None
No disruption

CVSS Vector v4.0

Weakness Type (CWE)

Vulnerable Products 4

Configuration From (including) Up to (excluding)
Team-Alembic Ash_Authentication
cpe:2.3:a:team-alembic:ash_authentication:*:*:*:*:*:*:*:*
4.9.1 4.15.0
Team-Alembic Ash_Authentication
cpe:2.3:a:team-alembic:ash_authentication:*:*:*:*:*:*:*:*
5.0.0-rc.0 5.0.0-rc.14
Team-Alembic Ash_Authentication_Phoenix
cpe:2.3:a:team-alembic:ash_authentication_phoenix:*:*:*:*:*:*:*:*
2.10.0 2.17.4
Team-Alembic Ash_Authentication_Phoenix
cpe:2.3:a:team-alembic:ash_authentication_phoenix:*:*:*:*:*:*:*:*
3.0.0-rc.0 3.0.0-rc.11