Medium

n8n: Per-Resource OAuth Consent Bypass via Unbound Refresh Token Resource Substitution

  • Disclosed: 10.09.2026
  • Updated: 11.10.2026 10:22

Impact

The OAuth token endpoint bound an authorization code's first access token to the consented resource, but not its refresh token. Refreshing only checked that the requested resource was registered, not that it matched the original grant. An OAuth client approved for one workflow could refresh with a different workflow's URL and get a valid, unapproved token for it. The patch binds refresh tokens to the granted resource and rejects mismatches.

Exploitation requires the attacker to register an OAuth client, convince an authenticated user to approve that client for one known protected resource, and know the URL of a second protected resource that the consenting user is permitted to execute.

Patches

The issue has been fixed in n8n versions 2.38.1 and 2.37.7. Users should upgrade to this version or later to remediate the vulnerability.

Workarounds

If upgrading is not immediately possible, administrators should consider the following temporary mitigations:

  • Restrict n8n instance access to fully trusted users only.
  • Deactivate MCP Trigger, form, and webhook workflows that are protected by the n8n OAuth server if they are not required.
  • Audit connected OAuth clients and revoke any that are not recognized or no longer needed.
  • Require re-authorization for all existing OAuth clients after upgrading, as previously issued refresh tokens did not store the original resource binding.

These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
npm package n8n >= 2.38.0, < 2.38.1, < 2.37.7 2.38.1, 2.37.7

References

CVSS score -
CVSS vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:L/VA:L/SC:N/SI:N/SA:N
Weakness (CWE)
CWE-863
Platform
npm
Package
n8n
Disclosed
10.09.2026
Updated
11.10.2026 10:22

Sources and licenses

OSV / GitHub Advisory Database - GHSA-cw9w-vv67-hf73 - CC BY 4.0

Vulnerability history: n8n

All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.

All (156) in the archive
Total entries
156
First → latest
05.2023 09.2026
Without a fix
1
Exploited in attacks
1

Severity breakdown

  • Critical 24
  • High 58
  • Medium 74

Disclosures per year

  1. 2023: 3
  2. 2024: 0
  3. 2025: 14
  4. 2026: 139
Severity:
  1. n8n: Per-Resource OAuth Consent Bypass via Unbound Refresh Token Resource Substitution this entry
    Medium CVE-2026-86073 >= 2.38.0, < 2.38.1, < 2.37.7 2.38.1, 2.37.7
  2. High CVE-2026-86083 < 1.123.76, >= 2.38.0, < 2.38.2, >= 2.0.0, < 2.37.7 1.123.76, 2.38.2, 2.37.7
  3. High CVE-2026-86082 < 1.123.76, >= 2.38.0, < 2.38.2, >= 2.0.0, < 2.37.7 1.123.76, 2.38.2, 2.37.7
  4. High CVE-2026-86081 < 1.123.76, >= 2.38.0, < 2.38.2, >= 2.0.0, < 2.37.7 1.123.76, 2.38.2, 2.37.7
  5. High CVE-2026-86075 >= 2.38.0, < 2.38.2, < 2.37.7 2.38.2, 2.37.7
  6. High CVE-2026-86076 < 1.123.76, >= 2.38.0, < 2.38.2, >= 2.0.0, < 2.37.7 1.123.76, 2.38.2, 2.37.7
  7. High CVE-2026-72749 < 1.123.67, >= 2.32.0, < 2.32.1, >= 2.0.0-rc.0, < 2.31.5 1.123.67, 2.32.1, 2.31.5
  8. High CVE-2026-72762 < 1.123.67, >= 2.32.0, < 2.32.1, >= 2.0.0-rc.0, < 2.31.5 1.123.67, 2.32.1, 2.31.5
  9. High CVE-2026-72763 < 1.123.67, >= 2.32.0, < 2.32.1, >= 2.0.0-rc.0, < 2.31.5 1.123.67, 2.32.1, 2.31.5
  10. High CVE-2026-72774 < 1.123.67, >= 2.32.0, < 2.32.1, >= 2.0.0-rc.0, < 2.31.5 1.123.67, 2.32.1, 2.31.5
  11. High CVE-2026-72765 >= 2.32.0, < 2.32.1, < 2.31.5 2.32.1, 2.31.5
  12. High CVE-2026-72766 < 1.123.67, >= 2.32.0, < 2.32.1, >= 2.0.0-rc.0, < 2.31.5 1.123.67, 2.32.1, 2.31.5
  13. High CVE-2026-72767 < 1.123.67, >= 2.32.0, < 2.32.1, >= 2.0.0-rc.0, < 2.31.5 1.123.67, 2.32.1, 2.31.5
  14. High CVE-2026-72770 < 1.123.67, >= 2.32.0, < 2.32.1, >= 2.0.0-rc.0, < 2.31.5 1.123.67, 2.32.1, 2.31.5
  15. High CVE-2026-72771 >= 2.32.0, < 2.32.1, < 2.31.5 2.32.1, 2.31.5
  16. High CVE-2026-72772 >= 2.32.0, < 2.32.1, < 2.31.5 2.32.1, 2.31.5
  17. High CVE-2026-65016 < 1.123.64, >= 2.30.0, < 2.30.1, >= 2.0.0-rc.0, < 2.29.8 1.123.64, 2.30.1, 2.29.8
  18. High CVE-2026-65591 < 1.123.64, >= 2.30.0, < 2.30.1, >= 2.0.0-rc.0, < 2.29.8 1.123.64, 2.30.1, 2.29.8
  19. High CVE-2026-59208 >= 2.28.0, < 2.28.1, < 2.27.4 2.28.1, 2.27.4
  20. High CVE-2026-59207 >= 2.28.0, < 2.28.1, < 2.27.4 2.28.1, 2.27.4
  21. High CVE-2026-59206 < 1.123.61, >= 2.28.0, < 2.28.1, >= 2.0.0-rc.0, < 2.27.4 1.123.61, 2.28.1, 2.27.4
  22. High CVE-2026-59209 < 1.123.61, >= 2.28.0, < 2.28.1, >= 2.0.0-rc.0, < 2.27.4 1.123.61, 2.28.1, 2.27.4
  23. High CVE-2026-65592 < 1.123.64, >= 2.30.0, < 2.30.1, >= 2.0.0-rc.0, < 2.29.8 1.123.64, 2.30.1, 2.29.8
  24. High CVE-2026-65597 < 1.123.64, >= 2.30.0, < 2.30.1, >= 2.0.0-rc.0, < 2.29.8 1.123.64, 2.30.1, 2.29.8
  25. High CVE-2026-65598 < 1.123.64, >= 2.30.0, < 2.30.1, >= 2.0.0-rc.0, < 2.29.8 1.123.64, 2.30.1, 2.29.8
  26. High CVE-2026-65015 >= 2.30.0, < 2.30.1, < 2.29.8 2.30.1, 2.29.8
  27. High · 7.7 CVE-2026-54304 < 1.123.55, >= 2.26.0, < 2.26.1, >= 2.0.0-rc.0, < 2.25.7 1.123.55, 2.26.1, 2.25.7
  28. High · 10.0 CVE-2026-54309 >= 2.26.0, < 2.26.2, < 2.25.7 2.26.2, 2.25.7
  29. High · 9.9 CVE-2026-54305 < 1.123.55, >= 2.26.0, < 2.26.2, >= 2.0.0-rc.0, < 2.25.7 1.123.55, 2.26.2, 2.25.7
  30. High · 9.6 CVE-2026-54307 < 1.123.55, >= 2.26.0, < 2.26.2, >= 2.0.0-rc.0, < 2.25.7 1.123.55, 2.26.2, 2.25.7
  31. High · 7.6 CVE-2026-54302 < 1.123.55, >= 2.26.0, < 2.26.2, >= 2.0.0-rc.0, < 2.25.7 1.123.55, 2.26.2, 2.25.7
  32. High · 8.5 CVE-2026-54312 < 2.24.0 2.24.0
  33. High · 7.6 CVE-2026-54301 < 1.123.55, >= 2.26.0, < 2.26.2, >= 2.0.0-rc.0, < 2.25.7 1.123.55, 2.26.2, 2.25.7
  34. High · 8.5 CVE-2026-49444 < 1.123.48, >= 2.22.0, < 2.22.4, >= 2.0.0-rc.0, < 2.21.8 1.123.48, 2.22.4, 2.21.8
  35. High · 8.1 CVE-2026-45732 < 1.123.43, >= 2.21.0, < 2.21.1, >= 2.0.0-rc.0, < 2.20.7 1.123.43, 2.21.1, 2.20.7
  36. High · 9.0 CVE-2026-44792 < 1.123.43, >= 2.21.0, < 2.21.1, >= 2.0.0-rc.0, < 2.20.7 1.123.43, 2.21.1, 2.20.7
  37. Critical · 9.9 CVE-2026-44791 < 1.123.43, >= 2.21.0, < 2.22.1, >= 2.0.0-rc.0, < 2.20.7 1.123.43, 2.22.1, 2.20.7
  38. Critical · 8.8 CVE-2026-44790 < 1.123.43, >= 2.21.0, < 2.22.1, >= 2.0.0-rc.0, < 2.20.7 1.123.43, 2.22.1, 2.20.7
  39. Critical · 9.9 CVE-2026-44789 < 1.123.43, >= 2.21.0, < 2.22.1, >= 2.0.0-rc.0, < 2.20.7 1.123.43, 2.22.1, 2.20.7
  40. Critical · 9.9 CVE-2026-42232 >= 2.18.0, < 2.18.1, >= 2.17.0, < 2.17.4, < 1.123.32 2.18.1, 2.17.4, 1.123.32
  41. Critical · 10.0 CVE-2026-42231 < 1.123.32, >= 2.18.0, < 2.18.1, >= 2.17.0, < 2.17.4 1.123.32, 2.18.1, 2.17.4
  42. High · 8.2 CVE-2026-42235 < 1.123.32, >= 2.18.0, < 2.18.1, >= 2.17.0, < 2.17.4 1.123.32, 2.18.1, 2.17.4
  43. High · 8.5 CVE-2026-42226 >= 2.17.0, < 2.17.5, < 1.123.33 2.17.5, 1.123.33
  44. High · 7.5 CVE-2026-42234 < 1.123.32, >= 2.18.0, < 2.18.1, >= 2.17.0, < 2.17.4 1.123.32, 2.18.1, 2.17.4
  45. High · 7.5 CVE-2026-42236 < 1.123.32, >= 2.18.0, < 2.18.1, >= 2.0.0, < 2.17.4 1.123.32, 2.18.1, 2.17.4
  46. High · 9.9 CVE-2026-33713 < 1.123.26, >= 2.14.0, < 2.14.1, >= 2.0.0-rc.0, < 2.13.3 1.123.26, 2.14.1, 2.13.3
  47. Critical · 9.9 CVE-2026-33696 >= 2.14.0, < 2.14.1, >= 2.0.0-rc.0, < 2.13.3, < 1.123.27 2.14.1, 2.13.3, 1.123.27
  48. High · 6.3 CVE-2026-33722 < 1.123.23, >= 2.0.0-rc.0, < 2.6.4 1.123.23, 2.6.4
  49. High · 8.2 CVE-2026-33665 >= 2.0.0-rc.0, < 2.4.0, < 1.121.0 2.4.0, 1.121.0
  50. High · 9.9 CVE-2026-33663 < 1.123.27, >= 2.14.0, < 2.14.1, >= 2.0.0-rc.0, < 2.13.3 1.123.27, 2.14.1, 2.13.3
  51. Critical · 9.9 CVE-2026-33660 >= 2.14.0, < 2.14.1, >= 2.0.0-rc.0, < 2.13.3, < 1.123.27 2.14.1, 2.13.3, 1.123.27
  52. High · 6.5 CVE-2026-27496 < 1.123.22, >= 2.10.0, < 2.10.1, >= 2.0.0-rc.0, < 2.9.3 1.123.22, 2.10.1, 2.9.3
  53. High · 5.4 CVE-2026-27578 < 1.123.22, >= 2.0.0, < 2.9.3, >= 2.10.0, < 2.10.1 1.123.22, 2.9.3, 2.10.1
  54. Critical · 9.9 CVE-2026-27577 < 1.123.22, >= 2.0.0, < 2.9.3, >= 2.10.0, < 2.10.1 1.123.22, 2.9.3, 2.10.1
  55. Critical · 8.5 CVE-2026-27498 < 1.123.8, >= 2.0.0, < 2.2.0 1.123.8, 2.2.0
  56. Critical · 9.9 CVE-2026-27497 < 1.123.22, >= 2.0.0, < 2.9.3, >= 2.10.0, < 2.10.1 1.123.22, 2.9.3, 2.10.1
  57. Critical CVE-2026-27495 < 1.123.22, >= 2.0.0, < 2.9.3, >= 2.10.0, < 2.10.1 1.123.22, 2.9.3, 2.10.1
  58. High · 9.9 CVE-2026-27494 < 1.123.22, >= 2.0.0, < 2.9.3, >= 2.10.0, < 2.10.1 1.123.22, 2.9.3, 2.10.1
  59. Critical · 9.0 CVE-2026-27493 < 1.123.22, >= 2.0.0, < 2.9.3, >= 2.10.0, < 2.10.1 1.123.22, 2.9.3, 2.10.1
  60. Critical · 9.9 CVE-2026-25115 < 2.4.8 2.4.8
  61. Critical CVE-2026-25056 < 1.118.0, >= 2.0.0, < 2.4.0 1.118.0, 2.4.0
  62. High CVE-2026-25055 >= 2.0.0, < 2.4.0, < 1.123.12 2.4.0, 1.123.12
  63. High CVE-2026-25054 >= 2.0.0, < 2.2.1, < 1.123.9 2.2.1, 1.123.9
  64. Critical CVE-2026-25053 >= 2.0.0, < 2.5.0, < 1.123.10 2.5.0, 1.123.10
  65. Critical CVE-2026-25052 >= 2.0.0, < 2.5.0, < 1.123.18 2.5.0, 1.123.18
  66. High CVE-2026-25051 >= 1.123.0, < 1.123.2, < 1.122.5 1.123.2, 1.122.5
  67. Critical CVE-2026-25049 < 1.123.17, >= 2.0.0, < 2.5.2 1.123.17, 2.5.2
  68. Critical CVE-2026-21893 >= 0.187.0, < 1.120.3 1.120.3
  69. High · 7.7 CVE-2025-61917 >= 1.65.0, < 1.114.3 1.114.3
  70. Critical · 9.9 CVE-2026-1470 < 1.123.17, >= 2.0.0, < 2.4.5, >= 2.5.0, < 2.5.1 1.123.17, 2.4.5, 2.5.1
  71. Critical · 10.0 CVE-2026-21858 >= 1.65.0, < 1.121.0 1.121.0
  72. Critical · 9.9 CVE-2026-21877 >= 0.123.0, < 1.121.3 1.121.3
  73. High · 7.1 CVE-2025-68697 >= 1.2.1, < 2.0.0 2.0.0
  74. Critical · 9.9 CVE-2025-68668 >= 1.0.0, < 2.0.0 2.0.0
  75. Critical · 9.9 Exploited in attacks CVE-2025-68613 >= 0.211.0, < 1.120.4, >= 1.121.0, < 1.121.1 1.120.4, 1.121.1
  76. Critical CVE-2025-65964 >= 0.123.1, < 1.119.2 1.119.2
  77. High · 8.8 CVE-2025-62726 < 1.113.0 1.113.0
  78. High · 7.5 CVE-2023-27564 < 0.216.1 0.216.1
  79. High · 8.8 CVE-2023-27563 < 0.216.1 0.216.1

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