CVE-2026-53512

CRITICALNVD 9.19.1—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.1 under NVD CVSS v3. EPSS exploit probability: 0.3%, top 81% 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, nvd
9.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.1Exploit: 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. Prior to 1.6.11, the legacy oidcProvider and mcp plugins expose OAuth token endpoints whose refresh_token grant authenticates only possession of the bound refreshToken row and matching client_id, without verifying the confidential client's client_secret, allowing an attacker with a valid refresh_token to mint access tokens and rotated refresh tokens through /api/auth/oauth2/token or /api/auth/mcp/token. The @better-auth/oauth-provider package is not affected. This issue is fixed in version 1.6.11.

CVSS v3
9.1
EG Score
9.1(medium)
EG Risk
56(Track)
EG Risk 56/100SSVC: 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
Severity91% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
19%
KEV
Not listed

Published

July 7, 2026

Last Modified

July 21, 2026

Advisory Details (4)

Auto-updated Aug 29, 2026
Patch available. Sources: github_commit, github_pr, github_release, github.
github Patch Available

OAuth refresh-token replay via missing client authentication on oidc-provider and mcp plugins · Advisory · better-auth/better-auth · GitHub

https://github.com/better-auth/better-auth/security/advisories/GHSA-pw9m-5jxm-xr6h
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_pr

fix(oidc-provider, mcp): authenticate confidential clients on refresh_token grant

Fix merged in better-auth/better-auth PR #9576 on 2026-05-12 — awaiting tagged release

https://github.com/better-auth/better-auth/pull/9576
github_commit

commit 1f2ff4215c4a (better-auth/better-auth)

Fix landed in better-auth/better-auth commit 1f2ff4215c4a — awaiting tagged release

https://github.com/better-auth/better-auth/commit/1f2ff4215c4affff0b140b0c0a712c0dde35659c

Vendor Advisories for CVE-2026-53512(1)

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

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFixed inDependents
better-auth—1.6.11—

Weakness Classification(4)

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

Data Freshness Timeline

(refreshed 11× in last 7d / 55× 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. 2026-08-30 07:42 UTCEG score recompute
  2. 2026-08-30 01:22 UTCEPSS rescore
  3. 2026-08-28 21:41 UTCEPSS rescore
  4. 2026-08-27 21:55 UTCEG score recompute
  5. 2026-08-27 14:25 UTCEPSS rescore
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  7. 2026-08-26 14:46 UTCEPSS rescore
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  9. 2026-08-25 13:49 UTCEPSS rescore
  10. 2026-08-24 20:38 UTCEG score recompute
  11. 2026-08-24 09:48 UTCEG score recompute
  12. 2026-08-23 02:36 UTCEG score recompute
  13. 2026-08-23 00:19 UTCEPSS rescore
  14. 2026-08-22 03:57 UTCEG score recompute
  15. 2026-08-21 23:49 UTCEPSS rescore
  16. 2026-08-20 23:10 UTCEG score recompute
  17. 2026-08-20 22:55 UTCEPSS rescore
  18. 2026-08-20 02:12 UTCEG score recompute
  19. 2026-08-19 17:04 UTCEPSS rescore
  20. 2026-08-18 20:47 UTCEG score recompute
  21. 2026-08-18 13:48 UTCEPSS rescore
  22. 2026-08-17 14:19 UTCEG score recompute
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  24. 2026-08-16 15:12 UTCEG score recompute
  25. 2026-08-16 14:56 UTCEPSS rescore
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  1. 2026-08-16 03:59 UTCEG score recompute
  2. 2026-08-16 02:14 UTCEPSS rescore
  3. 2026-08-15 01:50 UTCEG score recompute
  4. 2026-08-15 01:30 UTCEPSS rescore
  5. 2026-08-13 23:38 UTCEG score recompute
  6. 2026-08-13 22:00 UTCEPSS rescore
  7. 2026-08-12 17:32 UTCEG score recompute
  8. 2026-08-12 13:51 UTCEPSS rescore
  9. 2026-08-11 15:19 UTCEG score recompute
  10. 2026-08-11 00:21 UTCEG score recompute
  11. 2026-08-11 00:00 UTCEPSS rescore
  12. 2026-08-09 17:03 UTCEG score recompute
  13. 2026-08-09 13:46 UTCEPSS rescore
  14. 2026-08-08 18:39 UTCEG score recompute
  15. 2026-08-08 16:37 UTCEPSS rescore
  16. 2026-08-07 16:30 UTCEG score recompute
  17. 2026-08-06 14:22 UTCEG score recompute
  18. 2026-08-06 13:47 UTCEPSS rescore
  19. 2026-08-05 19:40 UTCEG score recompute
  20. 2026-08-05 19:17 UTCEPSS rescore
  21. 2026-08-04 18:15 UTCEG score recompute
  22. 2026-08-04 15:10 UTCEPSS rescore
  23. 2026-08-04 14:04 UTCEG score recompute
  24. 2026-08-04 10:39 UTCEPSS rescore
  25. 2026-08-03 13:50 UTCEG score recompute
  26. 2026-08-03 10:36 UTCEPSS rescore
  27. 2026-08-02 03:09 UTCEG score recompute
  28. 2026-08-02 02:27 UTCEPSS rescore
  29. 2026-08-01 04:45 UTCEG score recompute
  30. 2026-08-01 04:16 UTCEPSS rescore
  31. 2026-07-30 21:55 UTCEG score recompute
  32. 2026-07-30 16:28 UTCEPSS rescore
  33. 2026-07-30 12:35 UTCEG score recompute
  34. 2026-07-30 04:59 UTCEG score recompute
  35. 2026-07-30 01:30 UTCEPSS rescore
  36. 2026-07-28 17:16 UTCEG score recompute
  37. 2026-07-28 15:37 UTCEPSS rescore
  38. 2026-07-27 15:42 UTCEG score recompute
  39. 2026-07-26 16:24 UTCEG score recompute
  40. 2026-07-26 14:54 UTCEPSS rescore
  41. 2026-07-26 12:36 UTCEG score recompute
  42. 2026-07-25 14:18 UTCEPSS rescore
  43. 2026-07-24 14:18 UTCEPSS rescore
  44. 2026-07-23 14:18 UTCEPSS rescore
  45. 2026-07-23 03:19 UTCEG score recompute
  46. 2026-07-22 14:08 UTCEPSS rescore
  47. 2026-07-21 15:25 UTCEPSS rescore
  48. 2026-07-20 17:08 UTCEPSS rescore
  49. 2026-07-19 14:31 UTCEPSS rescore
  50. 2026-07-19 14:31 UTCEPSS rescore
  51. 2026-07-19 03:43 UTCEG score recompute
  52. 2026-07-19 02:29 UTCEPSS rescore
  53. 2026-07-18 10:04 UTCEPSS rescore
  54. 2026-07-16 17:03 UTCEPSS rescore
  55. 2026-07-15 17:28 UTCMITRE cvelistV5CVSS v4 → 9.1
  56. 2026-07-07 20:27 UTCEG score recompute

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-53512?
CVE-2026-53512 is a critical vulnerability published on July 7, 2026. Better Auth is an authentication and authorization library for TypeScript. Prior to 1.6.11, the legacy oidcProvider and mcp plugins expose OAuth token endpoints whose refreshtoken grant authenticates only possession of the bound refreshToken row and matching clientid, without verifying the…
When was CVE-2026-53512 disclosed?
CVE-2026-53512 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-2026-53512 actively exploited?
CVE-2026-53512 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 80.5% of all scored CVEs.
What is the CVSS score of CVE-2026-53512?
CVE-2026-53512 has a CVSS v3 base score of 9.1 (NVD).
How do I remediate CVE-2026-53512?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-53512, 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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