CVE-2026-86533
Insufficient Session Expiration vulnerability in team-alembic AshAuthentication and AshAuthentication Phoenix allows a revoked session to remain fully authenticated.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.65%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 4.0
- 9.1 CRITICALCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.65% probability · 50th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-613
- Source
- 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
EPSS 0.6% since 19 September 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://cna.erlef.org/cves/CVE-2026-86533.html
- https://github.com/team-alembic/ash_authentication/commit/a3f49f758f013d2ff086dd9c5ef2d94e921711b4
- https://github.com/team-alembic/ash_authentication/commit/e28e911caa9728d76329afdb0fb26742ffe4eeef
- https://github.com/team-alembic/ash_authentication/commit/fcaeb73f76f8f2e9aef8bf637690d2a20dd97596
- https://github.com/team-alembic/ash_authentication/security/advisories/GHSA-w374-hvrx-66hg
- https://github.com/team-alembic/ash_authentication_phoenix/commit/0135217e34e621dac79ae3d9559aeee49304b0aa
- https://github.com/team-alembic/ash_authentication_phoenix/commit/a3253fb4fc7145aeb403537af1c24d3a8d51ffb1
- https://github.com/team-alembic/ash_authentication_phoenix/commit/f7ab005a2aac09707a25521653c94893d328cc52
- https://github.com/team-alembic/ash_authentication_phoenix/security/advisories/GHSA-m6x4-4gvp-xwjr
- https://osv.dev/vulnerability/EEF-CVE-2026-86533
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.