CVE-2026-55196

CRITICALPre-NVD 9.19.1—
EchelonGraph scoreHIGH confidence

Score 9.1 from GitHub Security Advisory (severity: CRITICAL) published 2026-06-17. the CNA's CVSS baseline 9.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:vulncheck, epss, ghsa
Trending — 3 sources updated this week
9.1
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 9.1Exploit: NoneExposed: 0

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

Hermes WebUI before 0.51.409 contains an authentication bypass vulnerability in passkey registration endpoints that allows unauthenticated remote attackers to register arbitrary passkeys. When HERMES_WEBUI_PASSKEY=1 is enabled with no existing credentials, POST /api/auth/passkey/register/options and POST /api/auth/passkey/register endpoints are accessible without authentication, allowing attackers to claim the first passkey and gain permanent administrative control.

CVSS v3
9.1
EG Score
9.1(high)
EPSS
43.5%
KEV
Not listed

Published

June 17, 2026

Last Modified

June 23, 2026

Advisory Details (5)

Auto-updated Jun 17, 2026
Patch available. Sources: github_commit, github_pr, github_release.
generic

Hermes WebUI < 0.51.409 - Unauthenticated Passkey Registration via Authentication Bypass | Advisories | VulnCheck

https://www.vulncheck.com/advisories/hermes-webui-unauthenticated-passkey-registration-via-authentication-bypass
github_release Patch Available

v0.51.442

Patch available: nesquena/hermes-webui v0.51.442

https://github.com/nesquena/hermes-webui/releases/tag/v0.51.442
github_pr Patch Available

Release PC (v0.51.442): [security] require auth for passkey enrollment (#4171)

Patch available: nesquena/hermes-webui v0.51.451 (PR #4267 merged 2026-06-15)

https://github.com/nesquena/hermes-webui/pull/4267
github_pr

[security] fix(auth): require auth for passkey enrollment

Upstream fix in progress (PR #4171 · nesquena/hermes-webui, state=closed)

https://github.com/nesquena/hermes-webui/pull/4171
github_commit Patch Available

commit 4d90577e25d5 (nesquena/hermes-webui)

Patch available: nesquena/hermes-webui v0.51.451 (contains commit 4d90577e25d5)

https://github.com/nesquena/hermes-webui/commit/4d90577e25d5537cb07290eca3fb8abff3bab316

Vendor Advisories for CVE-2026-55196(1)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 86× in last 7d / 242× 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 242 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-55196?
CVE-2026-55196 is a critical vulnerability published on June 17, 2026. Hermes WebUI before 0.51.409 contains an authentication bypass vulnerability in passkey registration endpoints that allows unauthenticated remote attackers to register arbitrary passkeys. When HERMESWEBUIPASSKEY=1 is enabled with no existing credentials, POST /api/auth/passkey/register/options and…
When was CVE-2026-55196 disclosed?
CVE-2026-55196 was first published in the National Vulnerability Database on June 17, 2026, with the most recent update on June 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55196 actively exploited?
CVE-2026-55196 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 43.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-55196?
CVE-2026-55196 has a CVSS v4.0 base score of 9.1 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-55196?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55196, 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.

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