EEF-CVE-2026-86533 CVE-2026-86533 GHSA-m6x4-4gvp-xwjr

Revoked session accepted because the session jti is never checked in AshAuthentication and AshAuthentication Phoenix

Not rated yet Hex

Severity: 0.0 / 10; Unknown · CVSS 4.0
Exploit chance (EPSS): 0.91%; Chance of exploitation in the next 30 days. Higher than 59.93% of scored vulnerabilities.
Known exploited: No; Not in CISA's catalog
Weakness: CWE-613 Insufficient Session Expiration
Fix: Available; 2 packages have a fixed version

Description

Summary

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 versions

Hex

Package	Vulnerable	Fixed in
ash_authentication	`>= 4.9.1, < 4.15.0` `>= 5.0.0-rc.0, < 5.0.0-rc.14`	`4.15.0` `5.0.0-rc.14`
ash_authentication_phoenix	`>= 2.10.0, < 2.17.4` `>= 3.0.0-rc.0, < 3.0.0-rc.11`	`2.17.4` `3.0.0-rc.11`

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

ash_authentication Hex → `5.0.0-rc.14`

mix

{:ash_authentication, "~> 5.0.0-rc.14"} # then: mix deps.update ash_authentication

ash_authentication_phoenix Hex → `3.0.0-rc.11`

mix

{:ash_authentication_phoenix, "~> 3.0.0-rc.11"} # then: mix deps.update ash_authentication_phoenix

Severity breakdown

CVSS 4.0 0.0

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

Attack vector: Network
Attack complexity: Low
Attack requirements: Present
Privileges required: None
User interaction: None
Confidentiality (vulnerable system): High
Integrity (vulnerable system): High
Availability (vulnerable system): None
Confidentiality (subsequent systems): None
Integrity (subsequent systems): None
Availability (subsequent systems): None

Weakness

CWE-613: Insufficient Session Expiration

According to WASC, "Insufficient Session Expiration is when a web site permits an attacker to reuse old session credentials or session IDs for authorization."

How to prevent it

Implementation: Set sessions/credentials expiration date.

References

Advisories

Fixes and patches

Packages

Timeline

Sep 17, 2026 Published
Oct 13, 2026 Last updated by the source
Oct 31, 2026 Latest EPSS score

Advisory	Severity	Why it's related
EEF-CVE-2026-86688 Session id is not renewed on authentication in ash_authentication, allowing session fixation	Not rated yet	Also affects ash_authentication
EEF-CVE-2026-76949 Remember-me sign-in guard reads a session key that is never written in ash_authentication, allowing session replacement	Not rated yet	Also affects ash_authentication
EEF-CVE-2026-91039 dynamic_oidc identities are not namespaced by connection in ash_authentication, allowing cross-connection account takeover	Not rated yet	Also affects ash_authentication
EEF-CVE-2026-88952 OAuth2 sign-in attached to an existing account without an email comparison in AshAuthentication	Not rated yet	Also affects ash_authentication
EEF-CVE-2026-85500 `require_confirmed_with` is not enforced on the action and fails open on an unreadable attribute in AshAuthentication	Not rated yet	Also affects ash_authentication
EEF-CVE-2026-81632 Single-use sign-in token placed in a redirect query string in AshAuthenticationPhoenix	Not rated yet	Also affects ash_authentication
EEF-CVE-2026-80218 Sign-in token minted for one resource accepted by another in AshAuthentication	Not rated yet	Also affects ash_authentication
EEF-CVE-2026-78223 Token revocation record built from unverified JWT claims in AshAuthentication	Not rated yet	Also affects ash_authentication

Credits: James Harton, Jonatan Männchen / EEF, Peter Ullrich

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