CVE-2026-55205

MEDIUMPre-NVD 5.35.3—
EchelonGraph scoreMEDIUM confidence

Score 5.3 from GitHub Security Advisory published 2026-06-18. the CNA's CVSS baseline 5.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:vulncheck, epss, ghsa
Elevated
5.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 5.3Exploit: Elevated riskExposed: 0

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

Hermes WebUI before 0.51.468 contains a resource exhaustion vulnerability in the unauthenticated POST /api/onboarding/oauth/start endpoint that allows unbounded accumulation of in-memory flow state and daemon threads. Attackers can send repeated or concurrent requests to exhaust server memory and thread resources, potentially triggering repeated outbound device-code requests to upstream OAuth providers.

CVSS v3
5.3
EG Score
5.3(medium)
EG Risk
55(Attend)
EG Risk 55/100SSVC: Attend

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
Severity53% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
1%
EPSS %ILE
43%
KEV
Not listed

Published

June 18, 2026

Last Modified

July 14, 2026

Advisory Details (5)

Auto-updated Jun 18, 2026
Patch available. Sources: github_commit, github_pr, github_release.
github_pr

[security] fix(oauth): reuse pending onboarding flows

Upstream fix in progress (PR #3970 · nesquena/hermes-webui, state=closed)

https://github.com/nesquena/hermes-webui/pull/3970
generic

Hermes WebUI < 0.51.468 - Resource Exhaustion via Unauthenticated OAuth Flow Endpoint | Advisories | VulnCheck

https://www.vulncheck.com/advisories/hermes-webui-resource-exhaustion-via-unauthenticated-oauth-flow-endpoint
github_release Patch Available

v0.51.468

Patch available: nesquena/hermes-webui v0.51.468

https://github.com/nesquena/hermes-webui/releases/tag/v0.51.468
github_pr Patch Available

Release v0.51.468 — onboarding OAuth single-flight (#3970)

Patch available: nesquena/hermes-webui v0.51.470 (PR #4338 merged 2026-06-17)

https://github.com/nesquena/hermes-webui/pull/4338
github_commit Patch Available

commit ce272d9cd5f8 (nesquena/hermes-webui)

Patch available: nesquena/hermes-webui v0.51.470 (contains commit ce272d9cd5f8)

https://github.com/nesquena/hermes-webui/commit/ce272d9cd5f8e5a4521278f56eb5388010901646

Vendor Advisories for CVE-2026-55205(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 5× in last 7d / 47× 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 176 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-55205?
CVE-2026-55205 is a medium vulnerability published on June 18, 2026. Hermes WebUI before 0.51.468 contains a resource exhaustion vulnerability in the unauthenticated POST /api/onboarding/oauth/start endpoint that allows unbounded accumulation of in-memory flow state and daemon threads. Attackers can send repeated or concurrent requests to exhaust server memory and…
When was CVE-2026-55205 disclosed?
CVE-2026-55205 was first published in the National Vulnerability Database on June 18, 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-2026-55205 actively exploited?
CVE-2026-55205 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 57.2% of all scored CVEs.
What is the CVSS score of CVE-2026-55205?
CVE-2026-55205 has a CVSS v4.0 base score of 5.3 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-55205?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55205, 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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