Back to overview

CVE-2026-53517

HIGH
8.1
CVSS 3.1
Description
Better Auth is an authentication and authorization library for TypeScript. From 1.4.8-beta.7 until 1.6.11, the @better-auth/oauth-provider POST /oauth2/token endpoint on the refresh_token grant performs a non-atomic read, validate, revoke, and mint sequence on the oauthRefreshToken row, allowing concurrent requests with the same parent refresh token to pass the revoked check and create forked refresh-token families; the vulnerable range also includes embedded better-auth plugin versions before 1.6.0. This issue is fixed in version 1.6.11.

Metadata

CVE ID
CVE-2026-53517
State
PUBLISHED
Assigner
GitHub_M
Reserved
2026-06-09 17:30 UTC
Published
2026-07-15 17:33 UTC
Last updated
2026-07-15 19:21 UTC
Primary CWE
CWE-362
CWE-362: Concurrent Execution using Shared Resource with Imp…
Vendor / Product
better-auth / better-auth
Sources
cve.org  ·  NVD

Severity & Metrics

8.1 HIGH CVSS 3.1
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
SSVC — CISA Coordinator
Exploitation
none
Automatable
no
Tech. Impact
total
Affected products (2)
VendorProductPlatformVersions
@better-auth oauth-provider — >= 1.6.0, < 1.6.11
better-auth better-auth — >= 1.4.8-beta.7, < 1.6.0
Weakness (CWE)
CWESourceDescription
CWE-362 cna CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
CWE-367 cna CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition
CVSS scores (1)
ScoreSeverityVersionSourceVector
8.1 HIGH 3.1 cna CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
References (3)
Back to overview