> CVE-2026-86533 [CRITICAL]

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PUBLISHED
2026-09-17 14:17
MODIFIED
2026-09-17 14:17
CVSS_SCORE V3
9.1
EPSS (Prob. Exploit)
0.91%
Top 40.9%
DATA SOURCES:
NVD đź”— 2026-09-17 CWE MITRE đź”— 2026-10-01 FIRST EPSS đź”— 2026-10-16 OSV đź”— 2026-09-23

> 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.

> AFFECTED_PRODUCTS

ℹ️ Aucun produit affecté n'a encore été publié par NVD pour cette CVE.

> CVSS V3 METRICS

CVSS_VECTOR
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

> MÉTRIQUES CVSS DÉTAILLÉES

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Métrique Valeur Interprétation
AV (Vecteur d'Attaque)
Attack Vector
Network (N)
Exploit possible à distance via réseau (HTTP, API, etc.)
AC (Complexité d'Attaque)
Attack Complexity
Low (L)
Peu de conditions requises pour exploiter
PR (Privilèges Requis)
Privileges Required
None (N)
Aucune authentification requise
UI (Interaction Utilisateur)
User Interaction
None (N)
Aucune interaction utilisateur nécessaire
S (Périmètre)
Scope
Unchanged (U)
Impact reste dans le périmètre du composant compromis
C (Impact Confidentialité)
Confidentiality Impact
High (H)
Divulgation totale d'informations
I (Impact Intégrité)
Integrity Impact
High (H)
Modification totale des données possible
A (Impact Disponibilité)
Availability Impact
None (N)
Aucune interruption de service

> RÉSUMÉ DES IMPACTS

Confidentialité
High
Divulgation totale d'informations
Intégrité
High
Modification totale des données possible
Disponibilité
None
Aucune interruption de service

> WEAKNESSES

CWE-613

> CWE DETAILED DESCRIPTIONS

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."

> OSV (GOOGLE OPEN SOURCE VULNERABILITIES)

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

AFFECTED PACKAGES:
Unknown / Unknown
67 versions affected
ALIASES:
EEF-CVE-2026-86533, GHSA-m6x4-4gvp-xwjr

> HISTORIQUE DES MODIFICATIONS

Première apparition
17/09/2026 14:17
Source: NVD
📊 ENRICHISSEMENT 01/10/2026 06:01
CWE
Champ modifié: Description CWE
Ancienne valeur:
N/A
Nouvelle valeur:
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....
Total des modifications: 1 Dernière mise à jour: 3 weeks ago

> REFERENCES

https://cna.erlef.org/cves/CVE-2026-86533.html
https://github.com/team-alembic/ash_authentication/commit/a3f49f758f013d2ff086dd...
https://github.com/team-alembic/ash_authentication/commit/e28e911caa9728d76329af...
https://github.com/team-alembic/ash_authentication/commit/fcaeb73f76f8f2e9aef8bf...
https://github.com/team-alembic/ash_authentication/security/advisories/GHSA-w374...
https://github.com/team-alembic/ash_authentication_phoenix/commit/0135217e34e621...
https://github.com/team-alembic/ash_authentication_phoenix/commit/a3253fb4fc7145...
https://github.com/team-alembic/ash_authentication_phoenix/commit/f7ab005a2aac09...
https://github.com/team-alembic/ash_authentication_phoenix/security/advisories/G...
https://osv.dev/vulnerability/EEF-CVE-2026-86533
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