Better Auth: OAuth refresh-token replay via missing client authentication on oidc-provider and mcp plugins (better-auth better-auth)

CVE-2026-53512
CRITICAL 9.1

En bref

Source
NVD
EPSS
EPSS 0.27 % · centile 20 ()
État
PUBLISHED
Publiée
Mise à jour
Attribuée par
GitHub_M
Statut NVD
Analyzed

Description

Better Auth is an authentication and authorization library for TypeScript. Prior to 1.6.11, the legacy oidcProvider and mcp plugins expose OAuth token endpoints whose refresh_token grant authenticates only possession of the bound refreshToken row and matching client_id, without verifying the confidential client's client_secret, allowing an attacker with a valid refresh_token to mint access tokens and rotated refresh tokens through /api/auth/oauth2/token or /api/auth/mcp/token. The @better-auth/oauth-provider package is not affected. This issue is fixed in version 1.6.11.

Faiblesses (CWE)

  • CWE-287 — Authentification incorrecte
  • CWE-306 — Authentification absente sur une fonction critique
  • CWE-345 — Vérification insuffisante de l'authenticité des données
  • CWE-863 — Autorisation incorrecte

Références

Scores

VersionScoreVecteurÉvalué par
CVSS 4.0CRITICAL 9.1CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:NGitHub_M
CVSS 4.0CRITICAL 9.1CVSS: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:XNVD · security-advisories@github.com (Secondary)
CVSS 3.1CRITICAL 9.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:NNVD · nvd@nist.gov (Primary)

Avis

Références européennes

Configurations affectées (CPE NVD)

Produits affectés

ProduitVersions
better-auth · better-authaffected < 1.6.11

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD