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© 2026 FAUCET Technologies LLC. All rights reserved.

CVE-2026-53517

36
FAUCET Score

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.

First published: Jul 15, 2026Last modified: Jul 15, 2026

Impacted Technologies

VendorProductVersion(s)CPE
>= 1.6.0, < 1.6.11CPE matchmatch criteria
cpe:2.3:a:better-auth:better-auth\/oauth-provider:*:*:*:*:*:node.js:*:*
>= 1.4.9, < 1.6.11CPE matchmatch criteria
cpe:2.3:a:better-auth:better_auth:*:*:*:*:*:node.js:*:*
1.4.8CPE matchmatch criteria
cpe:2.3:a:better-auth:better_auth:1.4.8:-:*:*:*:node.js:*:*
1.4.8CPE matchmatch criteria
cpe:2.3:a:better-auth:better_auth:1.4.8:beta7:*:*:*:node.js:*:*

CVSS Data

CVSS version used by this source: 3.1

8.1HIGH

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
NONE
Exploitability Score
2.8
Impact Score
5.2
CvssVersion
3.1

Exploit Intelligence

EPSS Score
0.24%
Probability of exploitation in next 30 days
EPSS Percentile
15.3%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0024 is in the 4th percentile among its peer group of 17,829 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.3 Bluesky, 0.1 Mastodon, and 0.2 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (3)

github_advisorypatch availablevia nvd_reference
View patch
npmpatch availablevia ghsa
Product: @better-auth/oauth-providerFixed in: 1.6.11
npmpatch availablevia ghsa
Product: better-authFixed in: 1.6.0

Vendor Advisories (1)

npmGHSA-392p-2q2v-4372high

Better Auth: OAuth refresh-token rotation forks the token family on concurrent redemption

Jul 7, 2026

References

github.com / better-auth/better-auth/commit/c6918ecc9e3a75892169415d7f6c95b591b6a52d
Patch
github.com / better-auth/better-auth/releases/tag/v1.6.11
Release Notes
github.com / better-auth/better-auth/security/advisories/GHSA-392p-2q2v-4372
MitigationVendor Advisory