CVE-2026-55205

MEDIUMPre-NVD 5.35.3—
EchelonGraph scoreHIGH 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
Trending — 3 sources updated this weekElevated
5.3
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%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(high)
EPSS
21.9%
KEV
Not listed

Published

June 18, 2026

Last Modified

June 23, 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 27× in last 7d / 66× 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. 2026-07-07 23:42 UTCEG score recompute
  2. 2026-07-07 23:41 UTCGHSA enrichment
  3. 2026-07-07 13:46 UTCEPSS rescore
  4. 2026-07-07 13:46 UTCEPSS rescore
  5. 2026-07-07 01:45 UTCEG score recompute
  6. 2026-07-07 01:45 UTCGHSA enrichment
  7. 2026-07-06 16:27 UTCEPSS rescore
  8. 2026-07-06 16:27 UTCEPSS rescore
  9. 2026-07-06 03:48 UTCEG score recompute
  10. 2026-07-06 03:48 UTCGHSA enrichment
  11. 2026-07-06 02:23 UTCEPSS rescore
  12. 2026-07-06 02:23 UTCEPSS rescore
  13. 2026-07-05 05:52 UTCEG score recompute
  14. 2026-07-05 05:51 UTCGHSA enrichment
  15. 2026-07-05 02:31 UTCEPSS rescore
  16. 2026-07-05 02:30 UTCEPSS rescore
  17. 2026-07-04 07:52 UTCEG score recompute
  18. 2026-07-04 07:52 UTCGHSA enrichment
  19. 2026-07-04 06:31 UTCEPSS rescore
  20. 2026-07-04 06:31 UTCEPSS rescore
  21. 2026-07-03 09:05 UTCEG score recompute
  22. 2026-07-03 09:05 UTCGHSA enrichment
  23. 2026-07-02 11:09 UTCEG score recompute
  24. 2026-07-02 11:09 UTCGHSA enrichment
  25. 2026-07-01 15:07 UTCEPSS rescore
Show 41 more
  1. 2026-07-01 13:11 UTCEG score recompute
  2. 2026-07-01 13:11 UTCGHSA enrichment
  3. 2026-06-30 23:22 UTCEPSS rescore
  4. 2026-06-30 15:13 UTCEG score recompute
  5. 2026-06-30 15:12 UTCGHSA enrichment
  6. 2026-06-29 17:12 UTCEG score recompute
  7. 2026-06-29 17:11 UTCGHSA enrichment
  8. 2026-06-29 14:06 UTCEPSS rescore
  9. 2026-06-29 14:06 UTCEPSS rescore
  10. 2026-06-28 19:08 UTCEG score recompute
  11. 2026-06-28 19:08 UTCGHSA enrichment
  12. 2026-06-28 14:07 UTCEPSS rescore
  13. 2026-06-28 04:56 UTCEPSS rescore
  14. 2026-06-28 04:56 UTCEPSS rescore
  15. 2026-06-27 21:11 UTCEG score recompute
  16. 2026-06-27 21:11 UTCGHSA enrichment
  17. 2026-06-27 03:08 UTCEPSS rescore
  18. 2026-06-26 23:14 UTCEG score recompute
  19. 2026-06-26 23:14 UTCGHSA enrichment
  20. 2026-06-26 01:17 UTCEG score recompute
  21. 2026-06-26 01:17 UTCGHSA enrichment
  22. 2026-06-25 13:49 UTCEPSS rescore
  23. 2026-06-25 03:20 UTCEG score recompute
  24. 2026-06-25 03:20 UTCGHSA enrichment
  25. 2026-06-24 14:05 UTCEPSS rescore
  26. 2026-06-24 05:23 UTCEG score recompute
  27. 2026-06-24 05:23 UTCGHSA enrichment
  28. 2026-06-23 21:33 UTCEPSS rescore
  29. 2026-06-23 21:33 UTCEPSS rescore
  30. 2026-06-23 07:26 UTCEG score recompute
  31. 2026-06-23 07:26 UTCGHSA enrichment
  32. 2026-06-22 09:25 UTCEG score recompute
  33. 2026-06-22 09:25 UTCGHSA enrichment
  34. 2026-06-21 11:24 UTCEG score recompute
  35. 2026-06-21 11:23 UTCGHSA enrichment
  36. 2026-06-20 13:26 UTCEG score recompute
  37. 2026-06-20 13:26 UTCGHSA enrichment
  38. 2026-06-19 15:27 UTCEG score recompute
  39. 2026-06-19 15:26 UTCGHSA enrichment
  40. 2026-06-18 17:26 UTCEG score recompute
  41. 2026-06-18 17:24 UTCNVD updatefirst tracked

Related CVEs(same CWE)

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 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-2026-55205 actively exploited?
CVE-2026-55205 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 21.9% 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

Explore the affected products and dependency analysis for CVE-2026-55205

Explore →

Is Your Infrastructure Affected by CVE-2026-55205?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs