CVE-2026-86533
Published:September 17, 2026
Updated:September 22, 2026
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.
Affected Packages
https://github.com/team-alembic/ash_authentication_phoenix.git (GITHUB):
Affected version(s) >=3.0.0-rc.3 <3.0.0-rc.11Fix Suggestion:
Update to version 3.0.0-rc.11https://github.com/team-alembic/ash_authentication_phoenix.git (GITHUB):
Affected version(s) =2.17.0 <2.17.4Fix Suggestion:
Update to version 2.17.4https://github.com/team-alembic/ash_authentication.git (GITHUB):
Affected version(s) >=v4.9.1 <v4.15.0Fix Suggestion:
Update to version v4.15.0https://github.com/team-alembic/ash_authentication.git (GITHUB):
Affected version(s) >=v5.0.0-rc.0 <v5.0.0-rc.14Fix Suggestion:
Update to version v5.0.0-rc.14ash_authentication_phoenix (HEX):
Affected version(s) >=2.10.0 <2.17.4Fix Suggestion:
Update to version 2.17.4ash_authentication_phoenix (HEX):
Affected version(s) >=3.0.0-rc.0 <3.0.0-rc.11Fix Suggestion:
Update to version 3.0.0-rc.11ash_authentication (HEX):
Affected version(s) >=4.9.1 <4.15.0Fix Suggestion:
Update to version 4.15.0ash_authentication (HEX):
Affected version(s) >=5.0.0-rc.0 <5.0.0-rc.14Fix Suggestion:
Update to version 5.0.0-rc.14Related Resources (10)
Do you need more information?
Contact UsCVSS v4
Base Score:
9.1
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
PRESENT
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
9.1
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
NONE
Weakness Type (CWE)
Insufficient Session Expiration
EPSS
Base Score:
0.65