---
id: CVE-2026-86533
title: >-
  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_p…
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_p…
severity: critical
cvss: 9.1
cvssVector: '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'
cwe:
  - CWE-613
vendor: team-alembic
product: ash_authentication
affected:
  - ash_authentication >= 4.9.1 < 4.15.0
  - ash_authentication >= 5.0.0-rc.0 < 5.0.0-rc.14
  - >-
    team-alembic/ash_authentication >= fcaeb73f76f8f2e9aef8bf637690d2a20dd97596
    < *
  - ash_authentication_phoenix >= 2.10.0 < 2.17.4
  - ash_authentication_phoenix >= 3.0.0-rc.0 < 3.0.0-rc.11
  - >-
    team-alembic/ash_authentication_phoenix >=
    a3253fb4fc7145aeb403537af1c24d3a8d51ffb1 < *
  - >-
    team-alembic/ash_authentication_phoenix >=
    0135217e34e621dac79ae3d9559aeee49304b0aa < *
published: '2026-09-17'
updated: '2026-09-18'
sourceUpdated: '2026-09-18T18:16:18.527'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-86533'
references:
  - url: 'https://cna.erlef.org/cves/CVE-2026-86533.html'
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
  - url: >-
      https://github.com/team-alembic/ash_authentication/commit/a3f49f758f013d2ff086dd9c5ef2d94e921711b4
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
  - url: >-
      https://github.com/team-alembic/ash_authentication/commit/e28e911caa9728d76329afdb0fb26742ffe4eeef
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
  - url: >-
      https://github.com/team-alembic/ash_authentication/commit/fcaeb73f76f8f2e9aef8bf637690d2a20dd97596
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
  - url: >-
      https://github.com/team-alembic/ash_authentication/security/advisories/GHSA-w374-hvrx-66hg
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
  - url: >-
      https://github.com/team-alembic/ash_authentication_phoenix/commit/0135217e34e621dac79ae3d9559aeee49304b0aa
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
  - url: >-
      https://github.com/team-alembic/ash_authentication_phoenix/commit/a3253fb4fc7145aeb403537af1c24d3a8d51ffb1
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
  - url: >-
      https://github.com/team-alembic/ash_authentication_phoenix/commit/f7ab005a2aac09707a25521653c94893d328cc52
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
  - url: >-
      https://github.com/team-alembic/ash_authentication_phoenix/security/advisories/GHSA-m6x4-4gvp-xwjr
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
  - url: 'https://osv.dev/vulnerability/EEF-CVE-2026-86533'
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
tags:
  - nvd
  - cve.org
epss: 0.00908
epssPercentile: 0.58246
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: total
  timestamp: '2026-09-17T18:13:50.422619Z'
cvssSource: cna
ingestedAt: '2026-09-17T13:18:16.984Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.