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
5.3
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 1%CVSS: 5.3Exploit: NoneExposed: 0

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

Hermes WebUI before 0.51.468 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
41.3%
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 10× in last 7d / 69× 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.

  1. 2026-07-24 14:18 UTCEPSS rescore
  2. 2026-07-23 14:18 UTCEPSS rescore
  3. 2026-07-23 03:20 UTCEG score recompute
  4. 2026-07-22 14:08 UTCEPSS rescore
  5. 2026-07-21 15:25 UTCEPSS rescore
  6. 2026-07-20 17:08 UTCEPSS rescore
  7. 2026-07-19 14:31 UTCEPSS rescore
  8. 2026-07-19 14:31 UTCEPSS rescore
  9. 2026-07-19 02:29 UTCEPSS rescore
  10. 2026-07-18 10:04 UTCEPSS rescore
  11. 2026-07-17 03:43 UTCGHSA enrichment
  12. 2026-07-16 17:03 UTCEPSS rescore
  13. 2026-07-16 05:45 UTCGHSA enrichment
  14. 2026-07-15 16:57 UTCEPSS rescore
  15. 2026-07-15 16:57 UTCEPSS rescore
  16. 2026-07-15 07:47 UTCGHSA enrichment
  17. 2026-07-15 02:00 UTCEPSS rescore
  18. 2026-07-15 02:00 UTCEPSS rescore
  19. 2026-07-14 09:43 UTCGHSA enrichment
  20. 2026-07-13 22:31 UTCEPSS rescore
  21. 2026-07-13 11:25 UTCGHSA enrichment
  22. 2026-07-13 06:13 UTCEPSS rescore
  23. 2026-07-13 06:13 UTCEPSS rescore
  24. 2026-07-12 13:28 UTCGHSA enrichment
  25. 2026-07-12 05:46 UTCEPSS rescore
Show 55 more
  1. 2026-07-11 15:30 UTCGHSA enrichment
  2. 2026-07-11 08:27 UTCEPSS rescore
  3. 2026-07-11 08:27 UTCEPSS rescore
  4. 2026-07-10 17:32 UTCGHSA enrichment
  5. 2026-07-09 19:35 UTCGHSA enrichment
  6. 2026-07-09 19:10 UTCEPSS rescore
  7. 2026-07-09 19:10 UTCEPSS rescore
  8. 2026-07-08 21:38 UTCGHSA enrichment
  9. 2026-07-08 15:16 UTCEPSS rescore
  10. 2026-07-08 15:16 UTCEPSS rescore
  11. 2026-07-07 23:41 UTCGHSA enrichment
  12. 2026-07-07 13:46 UTCEPSS rescore
  13. 2026-07-07 13:46 UTCEPSS rescore
  14. 2026-07-07 01:45 UTCGHSA enrichment
  15. 2026-07-06 16:27 UTCEPSS rescore
  16. 2026-07-06 16:27 UTCEPSS rescore
  17. 2026-07-06 03:48 UTCGHSA enrichment
  18. 2026-07-06 02:23 UTCEPSS rescore
  19. 2026-07-06 02:23 UTCEPSS rescore
  20. 2026-07-05 05:51 UTCGHSA enrichment
  21. 2026-07-05 02:31 UTCEPSS rescore
  22. 2026-07-05 02:30 UTCEPSS rescore
  23. 2026-07-04 07:52 UTCGHSA enrichment
  24. 2026-07-04 06:31 UTCEPSS rescore
  25. 2026-07-04 06:31 UTCEPSS rescore
  26. 2026-07-03 09:05 UTCGHSA enrichment
  27. 2026-07-02 11:09 UTCGHSA enrichment
  28. 2026-07-01 15:07 UTCEPSS rescore
  29. 2026-07-01 13:11 UTCGHSA enrichment
  30. 2026-06-30 23:22 UTCEPSS rescore
  31. 2026-06-30 15:12 UTCGHSA enrichment
  32. 2026-06-29 17:11 UTCGHSA enrichment
  33. 2026-06-29 14:06 UTCEPSS rescore
  34. 2026-06-29 14:06 UTCEPSS rescore
  35. 2026-06-28 19:08 UTCGHSA enrichment
  36. 2026-06-28 14:07 UTCEPSS rescore
  37. 2026-06-28 04:56 UTCEPSS rescore
  38. 2026-06-28 04:56 UTCEPSS rescore
  39. 2026-06-27 21:11 UTCGHSA enrichment
  40. 2026-06-27 03:08 UTCEPSS rescore
  41. 2026-06-26 23:14 UTCGHSA enrichment
  42. 2026-06-26 01:17 UTCGHSA enrichment
  43. 2026-06-25 13:49 UTCEPSS rescore
  44. 2026-06-25 03:20 UTCGHSA enrichment
  45. 2026-06-24 14:05 UTCEPSS rescore
  46. 2026-06-24 05:23 UTCGHSA enrichment
  47. 2026-06-23 21:33 UTCEPSS rescore
  48. 2026-06-23 21:33 UTCEPSS rescore
  49. 2026-06-23 07:26 UTCGHSA enrichment
  50. 2026-06-22 09:25 UTCGHSA enrichment
  51. 2026-06-21 11:23 UTCGHSA enrichment
  52. 2026-06-20 13:26 UTCGHSA enrichment
  53. 2026-06-19 15:26 UTCGHSA enrichment
  54. 2026-06-18 17:26 UTCEG score recompute
  55. 2026-06-18 17:24 UTCNVD updatefirst tracked

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 41.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
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.

Dependency Blast Radius

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