CVE-2026-55196

CRITICALPre-NVD 9.19.1—
EchelonGraph scoreMEDIUM 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
9.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 9.1Exploit: None knownExposed: 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(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%
Exploitation1% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
46%
KEV
Not listed

Published

June 17, 2026

Last Modified

July 14, 2026

Advisory Details (5)

Auto-updated Sep 16, 2026
Patch available. Sources: github_pr, github_commit, 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_commit Patch Available

commit 4d90577e25d5 (nesquena/hermes-webui)

Patch available: nesquena/hermes-webui exp-v0.52.279 (contains commit 4d90577e25d5)

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

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

Patch available: nesquena/hermes-webui exp-v0.52.279 (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_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

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 10× in last 7d / 61× 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 423 total refreshes for this CVE.

  1. 2026-09-16 05:15 UTCEPSS rescore
  2. 2026-09-15 03:11 UTCEPSS rescore
  3. 2026-09-14 06:42 UTCGHSA enrichment
  4. 2026-09-14 02:22 UTCEG score recompute
  5. 2026-09-14 02:22 UTCGHSA enrichment
  6. 2026-09-13 16:47 UTCEPSS rescore
  7. 2026-09-13 14:08 UTCEG score recompute
  8. 2026-09-13 14:08 UTCGHSA enrichment
  9. 2026-09-11 14:53 UTCEPSS rescore
  10. 2026-09-10 09:35 UTCEPSS rescore
  11. 2026-09-08 22:01 UTCEPSS rescore
  12. 2026-09-07 16:01 UTCEPSS rescore
  13. 2026-09-06 13:47 UTCEPSS rescore
  14. 2026-09-04 05:06 UTCEPSS rescore
  15. 2026-09-02 14:12 UTCEPSS rescore
  16. 2026-09-01 13:54 UTCEPSS rescore
  17. 2026-09-01 04:40 UTCEPSS rescore
  18. 2026-08-31 01:36 UTCGHSA enrichment
  19. 2026-08-30 21:16 UTCEG score recompute
  20. 2026-08-30 21:16 UTCGHSA enrichment
  21. 2026-08-30 19:17 UTCEPSS rescore
  22. 2026-08-30 01:22 UTCEPSS rescore
  23. 2026-08-28 21:41 UTCEPSS rescore
  24. 2026-08-27 14:25 UTCEPSS rescore
  25. 2026-08-26 14:46 UTCEPSS rescore
Show 75 more
  1. 2026-08-25 13:49 UTCEPSS rescore
  2. 2026-08-25 07:10 UTCGHSA enrichment
  3. 2026-08-25 02:42 UTCGHSA enrichment
  4. 2026-08-24 22:22 UTCEG score recompute
  5. 2026-08-24 22:22 UTCGHSA enrichment
  6. 2026-08-24 05:18 UTCGHSA enrichment
  7. 2026-08-23 22:23 UTCGHSA enrichment
  8. 2026-08-23 17:49 UTCGHSA enrichment
  9. 2026-08-23 13:29 UTCGHSA enrichment
  10. 2026-08-23 08:36 UTCGHSA enrichment
  11. 2026-08-23 03:57 UTCEG score recompute
  12. 2026-08-23 03:57 UTCGHSA enrichment
  13. 2026-08-23 00:19 UTCEPSS rescore
  14. 2026-08-21 23:49 UTCEPSS rescore
  15. 2026-08-21 23:31 UTCGHSA enrichment
  16. 2026-08-21 19:10 UTCGHSA enrichment
  17. 2026-08-21 14:37 UTCGHSA enrichment
  18. 2026-08-21 10:17 UTCGHSA enrichment
  19. 2026-08-21 05:57 UTCGHSA enrichment
  20. 2026-08-21 01:37 UTCEG score recompute
  21. 2026-08-21 01:37 UTCGHSA enrichment
  22. 2026-08-20 22:55 UTCEPSS rescore
  23. 2026-08-20 21:18 UTCGHSA enrichment
  24. 2026-08-20 16:58 UTCGHSA enrichment
  25. 2026-08-20 12:31 UTCGHSA enrichment
  26. 2026-08-20 08:12 UTCEG score recompute
  27. 2026-08-20 08:12 UTCGHSA enrichment
  28. 2026-08-19 17:04 UTCEPSS rescore
  29. 2026-08-19 12:44 UTCGHSA enrichment
  30. 2026-08-19 08:08 UTCEG score recompute
  31. 2026-08-19 08:08 UTCGHSA enrichment
  32. 2026-08-18 13:48 UTCEPSS rescore
  33. 2026-08-17 14:54 UTCEG score recompute
  34. 2026-08-17 14:54 UTCGHSA enrichment
  35. 2026-08-17 13:47 UTCEPSS rescore
  36. 2026-08-17 10:35 UTCGHSA enrichment
  37. 2026-08-17 06:13 UTCGHSA enrichment
  38. 2026-08-17 01:12 UTCGHSA enrichment
  39. 2026-08-16 20:52 UTCGHSA enrichment
  40. 2026-08-16 16:21 UTCEG score recompute
  41. 2026-08-16 16:21 UTCGHSA enrichment
  42. 2026-08-16 14:56 UTCEPSS rescore
  43. 2026-08-16 12:00 UTCGHSA enrichment
  44. 2026-08-16 07:40 UTCGHSA enrichment
  45. 2026-08-16 03:21 UTCEG score recompute
  46. 2026-08-16 03:21 UTCGHSA enrichment
  47. 2026-08-16 02:14 UTCEPSS rescore
  48. 2026-08-15 23:02 UTCGHSA enrichment
  49. 2026-08-15 18:42 UTCGHSA enrichment
  50. 2026-08-15 14:22 UTCGHSA enrichment
  51. 2026-08-15 10:02 UTCGHSA enrichment
  52. 2026-08-15 05:42 UTCEG score recompute
  53. 2026-08-15 05:42 UTCGHSA enrichment
  54. 2026-08-15 01:30 UTCEPSS rescore
  55. 2026-08-15 01:22 UTCGHSA enrichment
  56. 2026-08-14 21:03 UTCGHSA enrichment
  57. 2026-08-14 16:43 UTCGHSA enrichment
  58. 2026-08-14 12:23 UTCGHSA enrichment
  59. 2026-08-14 08:04 UTCGHSA enrichment
  60. 2026-08-14 03:44 UTCGHSA enrichment
  61. 2026-08-13 23:25 UTCEG score recompute
  62. 2026-08-13 23:25 UTCGHSA enrichment
  63. 2026-08-13 22:00 UTCEPSS rescore
  64. 2026-08-13 19:04 UTCGHSA enrichment
  65. 2026-08-13 12:46 UTCGHSA enrichment
  66. 2026-08-13 08:27 UTCGHSA enrichment
  67. 2026-08-13 04:07 UTCGHSA enrichment
  68. 2026-08-12 23:47 UTCGHSA enrichment
  69. 2026-08-12 19:28 UTCGHSA enrichment
  70. 2026-08-12 15:08 UTCEG score recompute
  71. 2026-08-12 15:08 UTCGHSA enrichment
  72. 2026-08-12 13:51 UTCEPSS rescore
  73. 2026-08-12 10:49 UTCGHSA enrichment
  74. 2026-08-12 06:29 UTCGHSA enrichment
  75. 2026-08-12 02:10 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 July 14, 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 1% probability of exploitation in the next 30 days, which ranks it in the top 54.1% of all scored CVEs.
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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