> CVE-2026-66884 [LOW]

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PUBLISHED
2026-08-04 12:16
MODIFIED
2026-08-04 12:16
CVSS_SCORE V3
2.1
EPSS (Prob. Exploit)
0.26%
Top 82.8%
DATA SOURCES:
NVD 🔗 2026-08-04 CWE MITRE 🔗 2026-11-01 FIRST EPSS 🔗 2026-11-01 OSV 🔗 2026-11-02

> DESCRIPTION

Cross-Site Request Forgery vulnerability in Erlang Ecosystem Foundation oidcc_plug (Oidcc.Plug.AuthorizationCallback module) allows an attacker to make a victim's browser complete an authorization flow the victim never initiated. This vulnerability is associated with program file lib/oidcc/plug/authorization_callback.ex and program routine Oidcc.Plug.AuthorizationCallback.call/2. A callback request that carries no Oidcc.Plug.Authorize session is processed with every security check disabled rather than being rejected. call/2 substitutes permissive defaults for the absent session, and each downstream check treats its value as nothing to compare and returns :ok, so the nonce, state, PKCE, peer IP and user agent checks are all skipped. A separate clause of check_state/2 also accepts a state-less request when a verifier is present. An attacker obtains an authorization code for their own provider account, then induces the victim to visit the callback endpoint with that code and no state parameter. The application signs the victim in as the attacker, so the victim's subsequent actions occur in the attacker's account where the attacker can read them. Applications reusing one callback for both signing in and linking a provider account are further exposed to account takeover, the attacker's account becoming linked to the victim's. The permissive fallback serves no conforming flow. Third-party-initiated login reaches a relying party at a separate login initiation endpoint and causes it to send a fresh authentication request, and this library implements no such endpoint. Oidcc.Plug.Authorize always sends a state parameter, which an authorization server must echo, so no legitimate callback lacks one. This issue affects oidcc_plug: from 0.2.0-beta.1 before 0.5.0.

> 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:A/VC:L/VI:L/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:A/VC:L/VI:L/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
Required (R)
Nécessite une action utilisateur (clic lien, ouverture fichier, etc.)
S (Périmètre)
Scope
Unchanged (U)
Impact reste dans le périmètre du composant compromis
C (Impact Confidentialité)
Confidentiality Impact
Low (L)
Divulgation limitée d'informations
I (Impact Intégrité)
Integrity Impact
Low (L)
Modification limitée des données possible
A (Impact Disponibilité)
Availability Impact
None (N)
Aucune interruption de service

> RÉSUMÉ DES IMPACTS

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

> WEAKNESSES

CWE-352

> CWE DETAILED DESCRIPTIONS

CWE-352: Cross-Site Request Forgery - The web application does not, or cannot, sufficiently verify whether a request was intentionally provided by the user who sent the request, which could have originated from an unauthorized actor.

> OSV (GOOGLE OPEN SOURCE VULNERABILITIES)

Oidcc.Plug.AuthorizationCallback accepts callbacks with no authorize session or no state parameter, defeating CSRF protection

AFFECTED PACKAGES:
Unknown / Unknown
8 versions affected
ALIASES:
EEF-CVE-2026-66884, GHSA-fg66-w5gp-22cr

> HISTORIQUE DES MODIFICATIONS

Première apparition
04/08/2026 12:16
Source: NVD
📊 ENRICHISSEMENT 01/11/2026 06:59
CWE
Champ modifié: Description CWE
Ancienne valeur:
CWE-352: Cross-Site Request Forgery (CSRF) - The web application does not, or cannot, sufficiently verify whether a request was intentionally provided by the user who sent the request, which could hav...
Nouvelle valeur:
CWE-352: Cross-Site Request Forgery - The web application does not, or cannot, sufficiently verify whether a request was intentionally provided by the user who sent the request, which could have origi...
📊 ENRICHISSEMENT 01/09/2026 06:02
CWE
Champ modifié: Description CWE
Ancienne valeur:
N/A
Nouvelle valeur:
CWE-352: Cross-Site Request Forgery (CSRF) - The web application does not, or cannot, sufficiently verify whether a request was intentionally provided by the user who sent the request, which could hav...
Total des modifications: 2 Dernière mise à jour: 3 days ago

> REFERENCES

https://cna.erlef.org/cves/CVE-2026-66884.html
https://github.com/erlef/oidcc_plug/commit/97d75afc57826dca31989b47d6e2a3c136039...
https://github.com/erlef/oidcc_plug/security/advisories/GHSA-fg66-w5gp-22cr
https://osv.dev/vulnerability/EEF-CVE-2026-66884
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