CVE-2026-67336

HIGHPre-NVD 8.78.7—
EchelonGraph scoreMEDIUM confidence

Score 8.7 from GitHub Security Advisory (severity: CRITICAL) published 2026-08-01. A secondary CVSS source baseline 8.7; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
8.7EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 8.7Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

better-auth versions before 1.6.11 contain insecure cryptographic defaults in the oidcProvider and mcp plugins that advertise the none algorithm and accept plain PKCE by default. Attackers can exploit algorithm negotiation to accept unsigned tokens or intercept authorization codes when PKCE plain is used instead of the required S256 method.

CVSS v3
8.7
EG Score
8.7HIGHmedium confidence
EG Risk
39
EG Risk 39/100CISA SSVC

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
Severity87% × 45%
Exploitation0% × 40%
Automatability0% × 15%
CISA SSVC: Track at every mission impact level.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.2%
EPSS %ILE
13th
KEV
Not listed

CISA SSVCTrack at every mission impact level.

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

August 1, 2026

Last Modified

September 8, 2026

Advisory Details (2)

Auto-updated Aug 1, 2026
Patch available. Sources: github.
generic

better-auth before 1.6.11 Insecure Cryptographic Defaults via oidcProvider | Advisories | VulnCheck

https://www.vulncheck.com/advisories/better-auth-before-insecure-cryptographic-defaults-via-oidcprovider
github Patch Available

Insecure cryptographic defaults in oidcProvider: alg=none advertised and plain PKCE accepted by default · Advisory · better-auth/better-auth · GitHub

https://github.com/better-auth/better-auth/security/advisories/GHSA-9h47-pqcx-hjr4

Vendor Advisories for CVE-2026-67336(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(1)

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

Data Freshness Timeline

(refreshed 19× in last 7d / 83× 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.

Showing the most recent 100 of 205 total refreshes for this CVE.

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

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-67336?
CVE-2026-67336 is a high vulnerability published on August 1, 2026. better-auth versions before 1.6.11 contain insecure cryptographic defaults in the oidcProvider and mcp plugins that advertise the none algorithm and accept plain PKCE by default. Attackers can exploit algorithm negotiation to accept unsigned tokens or intercept authorization codes when PKCE plain…
When was CVE-2026-67336 disclosed?
CVE-2026-67336 was first published on August 1, 2026, with the most recent update on September 8, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-67336 actively exploited?
CVE-2026-67336 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (13th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-67336?
CVE-2026-67336 has a CVSS base score of 8.7 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-67336?
A fix for CVE-2026-67336 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-67336 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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