CVE-2026-53512

CRITICALNVD 9.19.1
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to NVD's CVSS score.

This critical-severity CVE scores 9.1 under NVD CVSS v3. EPSS exploit probability: 0.3% (18th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from NVD CVSS v3
Sources: EPSS, NVD CVSS v3
9.1EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 9.1Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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
9.1CRITICALmedium confidence
EG Risk
56
EG Risk 56/100

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 (value × EchelonGraph’s weight)
Severity91% × 45%
The EG Score, 9.1 of 10.
Exploitation0.3% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.3%
EPSS %ILE
18th
KEV
Not listed

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)3 days if the affected system is publicly exposed; 60 days if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

July 7, 2026

Last Modified

July 21, 2026

Advisory Details (4)

Auto-updated Sep 16, 2026
Patch available. Sources: github_release, github, github_commit, github_pr.
GitHub advisoryMentions a patch (unverified)

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 pull request

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 rangeFix by version rangeDependents
better-auth—
  • every version up to 1.6.11: fixed in 1.6.11
—

Weakness Classification(4)

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

Data Freshness Timeline

(refreshed 14× in last 7d / 34× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 100 of 132 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 32 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  2. 2026-10-14 01:59 UTCEG score recompute
  3. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  4. 2026-10-12 22:16 UTCEG score recompute
  5. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  6. 2026-10-12 15:57 UTCEG score recompute
  7. 2026-10-11 19:40 UTCEG score recompute
  8. 2026-10-11 16:55 UTCEG score recompute
  9. 2026-10-11 14:19 UTCEG score recompute
  10. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  11. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  12. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  13. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  14. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  15. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  16. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  17. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  18. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  19. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  20. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  21. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  22. 2026-09-29 15:22 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  23. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  24. 2026-09-28 13:36 UTCEG score recompute
  25. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.3% · 17th percentile
Show 75 more
  1. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  2. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  3. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  4. 2026-09-23 06:16 UTCEG score recompute
  5. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  6. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  7. 2026-09-18 05:49 UTCEG score recompute
  8. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  9. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  10. 2026-09-13 23:53 UTCEG score recompute
  11. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  12. 2026-09-13 08:29 UTCEG score recompute
  13. 2026-09-12 03:42 UTCEG score recompute
  14. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  15. 2026-09-10 09:35 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  16. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  17. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  18. 2026-09-06 14:08 UTCEG score recompute
  19. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  20. 2026-09-05 22:53 UTCEG score recompute
  21. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  22. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  23. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  24. 2026-09-01 04:40 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  25. 2026-08-30 20:31 UTCEG score recompute
  26. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  27. 2026-08-30 07:42 UTCEG score recompute
  28. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  29. 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  30. 2026-08-27 21:55 UTCEG score recompute
  31. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  32. 2026-08-27 01:57 UTCEG score recompute
  33. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  34. 2026-08-25 15:58 UTCEG score recompute
  35. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  36. 2026-08-24 20:38 UTCEG score recompute
  37. 2026-08-24 09:48 UTCEG score recompute
  38. 2026-08-23 02:36 UTCEG score recompute
  39. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  40. 2026-08-22 03:57 UTCEG score recompute
  41. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  42. 2026-08-20 23:10 UTCEG score recompute
  43. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  44. 2026-08-20 02:12 UTCEG score recompute
  45. 2026-08-19 17:04 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  46. 2026-08-18 20:47 UTCEG score recompute
  47. 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  48. 2026-08-17 14:19 UTCEG score recompute
  49. 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  50. 2026-08-16 15:12 UTCEG score recompute
  51. 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  52. 2026-08-16 03:59 UTCEG score recompute
  53. 2026-08-16 02:14 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  54. 2026-08-15 01:50 UTCEG score recompute
  55. 2026-08-15 01:30 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  56. 2026-08-13 23:38 UTCEG score recompute
  57. 2026-08-13 22:00 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  58. 2026-08-12 17:32 UTCEG score recompute
  59. 2026-08-12 13:51 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  60. 2026-08-11 15:19 UTCEG score recompute
  61. 2026-08-11 00:21 UTCEG score recompute
  62. 2026-08-11 00:00 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  63. 2026-08-09 17:03 UTCEG score recompute
  64. 2026-08-09 13:46 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  65. 2026-08-08 18:39 UTCEG score recompute
  66. 2026-08-08 16:37 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  67. 2026-08-07 16:30 UTCEG score recompute
  68. 2026-08-06 14:22 UTCEG score recompute
  69. 2026-08-06 13:47 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  70. 2026-08-05 19:40 UTCEG score recompute
  71. 2026-08-05 19:17 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  72. 2026-08-04 18:15 UTCEG score recompute
  73. 2026-08-04 15:10 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  74. 2026-08-04 14:04 UTCEG score recompute
  75. 2026-08-04 10:39 UTCEPSS rescoreEPSS 0.2% · 11th percentile

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-53512?
CVE-2026-53512 is a critical-severity vulnerability; its CVE record was 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 the CVE record for CVE-2026-53512 published?
The CVE record for CVE-2026-53512 was published on July 7, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of July 21, 2026; the record at its source may have been updated since.
Is CVE-2026-53512 actively exploited?
CVE-2026-53512 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (18th percentile of EPSS-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?
A fix for CVE-2026-53512 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-53512 are linked in the Vendor Advisories panel on this page.

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