Free and open · new CVEs checked every 20 minutesStatusRSSOpen dataContact

CVE-2026-53517: Better Auth is an authentication and authorization library for TypeScript

37
Routine
HIGH 8.1UPGRADEUPGRADE

CVE-2026-53517 is a high-severity flaw (CVSS 8.1) affecting better-auth\/oauth-provider, better auth. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 incl

Why this priority

  • High severity

A fixed release or distro patch exists.

Risk facts

CVSS score8.1 (High)
Attack vectorNetwork (remote)
Attack complexityLow
Privileges neededLow
User interactionNone
EPSS exploit chance0.4% (top 64%)
CISA exploited listNo
WeaknessCWE-362, CWE-367
Published2026-07-15
Last modified2026-07-21
Publisher (CNA): GitHub, Inc. · Vendor: better-auth

Share: LinkedIn · X · Reddit

Last updated 2026-07-21 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

better-auth better-auth\/oauth-provider UPGRADE
Affected: >= 1.6.0 and < 1.6.11
Fixed in: 1.6.11
Safe to downgrade to: a release before 1.6.0
1. Check installed version
npm ls better-authoauth-provider
2. UPGRADE to 1.6.11
npm install better-authoauth-provider@">=1.6.11"
3. If no update is available yet, DOWNGRADE to a release before 1.6.0
npm view better-authoauth-provider versions npm install better-authoauth-provider@"<1.6.0"
Downgrade risk
Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.
After downgrade
Restart the service, and keep the package held until a fixed release ships.
better-auth better auth UPGRADE
Affected: >= 1.4.9 and < 1.6.11 · 1.4.8 · 1.4.8 beta7
Fixed in: 1.6.11
Safe to downgrade to: a release before 1.4.8
1. Check installed version
npm ls better-auth
2. UPGRADE to 1.6.11
npm install better-auth@">=1.6.11"
3. If no update is available yet, DOWNGRADE to a release before 1.4.8
npm view better-auth versions npm install better-auth@"<1.4.8"
Downgrade risk
Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.
After downgrade
Restart the service, and keep the package held until a fixed release ships.
Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-53517?

better-auth\/oauth-provider: upgrade to 1.6.11; better auth: upgrade to 1.6.11. Exact commands for each OS are on this page.

Is CVE-2026-53517 being exploited?

CVE-2026-53517 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-53517 affect?

CVE-2026-53517 affects better-auth\/oauth-provider, better auth. Severity is high (CVSS 8.1). 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,

How urgent is CVE-2026-53517?

Priority 37/100. High severity

Related CVEs

References

← Back to latest CVEs

Get the weekly exploited-CVE digest by emailThe CVEs being attacked this week and how to fix them. No spam, unsubscribe any time.