CVE-2026-53517

HIGHPre-NVD 8.18.1—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.1 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4%, top 65% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
8.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.1Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
8.1
EG Score
8.1(medium)
EG Risk
37(Track)
EG Risk 37/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity81% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
36%
KEV
Not listed

Published

July 7, 2026

Last Modified

July 21, 2026

Advisory Details (3)

Auto-updated Jul 15, 2026
Patch available. Sources: github_commit, github_release, github.
github Patch Available

@better-auth/oauth-provider: OAuth refresh-token rotation forks the token family on concurrent redemption · Advisory · better-auth/better-auth · GitHub

https://github.com/better-auth/better-auth/security/advisories/GHSA-392p-2q2v-4372
github_release Patch Available

v1.6.11

Patch available: better-auth/better-auth v1.6.11

https://github.com/better-auth/better-auth/releases/tag/v1.6.11
github_commit

commit c6918ecc9e3a (better-auth/better-auth)

Fix landed in better-auth/better-auth commit c6918ecc9e3a — awaiting tagged release

https://github.com/better-auth/better-auth/commit/c6918ecc9e3a75892169415d7f6c95b591b6a52d

Vendor Advisories for CVE-2026-53517(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(2 across 1 ecosystem)
npm(2)
PackageVulnerable rangeFixed inDependents
better-auth—1.6.0—
@better-auth/oauth-provider—1.6.11—

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 7× in last 7d / 43× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-11 14:53 UTCEPSS rescore
  2. 2026-09-10 09:35 UTCEPSS rescore
  3. 2026-09-08 22:01 UTCEPSS rescore
  4. 2026-09-07 16:01 UTCEPSS rescore
  5. 2026-09-06 14:07 UTCEG score recompute
  6. 2026-09-06 13:47 UTCEPSS rescore
  7. 2026-09-05 22:53 UTCEG score recompute
  8. 2026-09-04 05:06 UTCEPSS rescore
  9. 2026-09-02 14:12 UTCEPSS rescore
  10. 2026-09-01 13:54 UTCEPSS rescore
  11. 2026-09-01 04:40 UTCEPSS rescore
  12. 2026-08-30 19:17 UTCEPSS rescore
  13. 2026-08-30 07:42 UTCEG score recompute
  14. 2026-08-30 01:22 UTCEPSS rescore
  15. 2026-08-28 21:41 UTCEPSS rescore
  16. 2026-08-27 21:54 UTCEG score recompute
  17. 2026-08-27 14:25 UTCEPSS rescore
  18. 2026-08-27 01:53 UTCEG score recompute
  19. 2026-08-26 14:46 UTCEPSS rescore
  20. 2026-08-26 12:58 UTCEG score recompute
  21. 2026-08-25 13:49 UTCEPSS rescore
  22. 2026-08-25 00:24 UTCEG score recompute
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  24. 2026-08-23 00:19 UTCEPSS rescore
  25. 2026-08-22 03:57 UTCEG score recompute
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  1. 2026-08-21 23:49 UTCEPSS rescore
  2. 2026-08-21 04:10 UTCEG score recompute
  3. 2026-08-20 22:55 UTCEPSS rescore
  4. 2026-08-20 02:10 UTCEG score recompute
  5. 2026-08-19 17:04 UTCEPSS rescore
  6. 2026-08-18 22:29 UTCEG score recompute
  7. 2026-08-18 13:48 UTCEPSS rescore
  8. 2026-08-17 22:33 UTCEG score recompute
  9. 2026-08-17 13:47 UTCEPSS rescore
  10. 2026-08-16 18:02 UTCEG score recompute
  11. 2026-08-16 14:56 UTCEPSS rescore
  12. 2026-08-16 06:36 UTCEG score recompute
  13. 2026-08-16 02:14 UTCEPSS rescore
  14. 2026-08-15 07:49 UTCEG score recompute
  15. 2026-08-15 01:30 UTCEPSS rescore
  16. 2026-08-14 07:23 UTCEG score recompute
  17. 2026-08-13 22:00 UTCEPSS rescore
  18. 2026-08-12 21:12 UTCEG score recompute
  19. 2026-08-12 13:51 UTCEPSS rescore
  20. 2026-08-11 22:21 UTCEG score recompute
  21. 2026-08-11 10:57 UTCEG score recompute
  22. 2026-08-11 00:00 UTCEPSS rescore
  23. 2026-08-10 00:45 UTCEG score recompute
  24. 2026-08-09 13:46 UTCEPSS rescore
  25. 2026-08-09 01:57 UTCEG score recompute
  26. 2026-08-08 16:37 UTCEPSS rescore
  27. 2026-08-08 03:08 UTCEG score recompute
  28. 2026-08-06 16:56 UTCEG score recompute
  29. 2026-08-06 13:47 UTCEPSS rescore
  30. 2026-08-06 05:32 UTCEG score recompute
  31. 2026-08-05 19:17 UTCEPSS rescore
  32. 2026-08-04 17:08 UTCEG score recompute
  33. 2026-08-04 15:10 UTCEPSS rescore
  34. 2026-08-04 10:39 UTCEPSS rescore
  35. 2026-08-03 18:19 UTCEG score recompute
  36. 2026-08-03 10:36 UTCEPSS rescore
  37. 2026-08-02 07:39 UTCEG score recompute
  38. 2026-08-02 02:27 UTCEPSS rescore
  39. 2026-07-30 22:14 UTCEG score recompute
  40. 2026-07-30 16:28 UTCEPSS rescore
  41. 2026-07-30 10:50 UTCEG score recompute
  42. 2026-07-30 01:30 UTCEPSS rescore
  43. 2026-07-29 00:07 UTCEG score recompute
  44. 2026-07-28 15:37 UTCEPSS rescore
  45. 2026-07-28 00:38 UTCEG score recompute
  46. 2026-07-26 23:59 UTCEG score recompute
  47. 2026-07-26 14:54 UTCEPSS rescore
  48. 2026-07-26 12:35 UTCEG score recompute
  49. 2026-07-25 14:18 UTCEPSS rescore
  50. 2026-07-24 14:18 UTCEPSS rescore
  51. 2026-07-23 14:18 UTCEPSS rescore
  52. 2026-07-23 03:19 UTCEG score recompute
  53. 2026-07-22 14:08 UTCEPSS rescore
  54. 2026-07-21 15:25 UTCEPSS rescore
  55. 2026-07-20 17:08 UTCEPSS rescore
  56. 2026-07-19 02:29 UTCEPSS rescore
  57. 2026-07-18 10:04 UTCEPSS rescore
  58. 2026-07-16 17:03 UTCEPSS rescore
  59. 2026-07-07 21:13 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-53517?
CVE-2026-53517 is a high vulnerability published on July 7, 2026. 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…
When was CVE-2026-53517 disclosed?
CVE-2026-53517 was first published in the National Vulnerability Database on July 7, 2026, with the most recent update on July 21, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-53517 actively exploited?
CVE-2026-53517 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 64.4% of all scored CVEs.
What is the CVSS score of CVE-2026-53517?
CVE-2026-53517 has a CVSS v3 base score of 8.1 (NVD).
How do I remediate CVE-2026-53517?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-53517, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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