CVE-2026-53517
Review this vulnerability's source-backed evidence, with unavailable values and read failures kept distinct.
A permanent, source-backed tracker page. Values are shown only when returned; explicit gaps and read failures remain different states.
Detection and validation
Mapped metadata availability only. These signals do not change priority.
Sigma
Not mapped by tracked sources.
Atomic
Not mapped by tracked sources.
Nuclei
Not mapped by tracked sources.
What it is
ReportedBetter 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.
Source reported · Source: NVD · Source last published: · Source description excerpt; complete tracked detail loads below. · Source last updated: · Tracker data as of:
What is affected
ReportedBetter Auth; Better Auth. Product-level identification only; no affected-version conclusion is available from this field.
Source reported · Source: NVD · Source last published: · Source last updated: · Tracker data as of:
Urgency and basis
ReportedTrack · 121.8
Tracker computed · Tracker decision tier from the evidence detailed below · Source last updated: · Tracker data as of:
Exploitation evidence
Not reportedNot reported by tracked sources.
What to do
ReportedA source remediation link is available. Validate that guidance against the affected product and your environment.
Source remediation ↗Source reported · Tracked source remediation field · Source last updated: · Tracker data as of:
Evidence detail
Loading the full tracker evidence record…