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TI-2026-39885 Aliases CVE-2026-55205GHSA-hq7f-wv7c-w9mp

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

Priority HIGH 70CWE-770Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · Low
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-770.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00524 44th percentileScored 2026-11-07
Fix Fixed hermes-webui (nesquena): 0.51.468

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
nesquenahermes-webuibefore 0.51.4680.51.468Patch availableCNA
  • hermes-webui Vendornesquena Affected before 0.51.468 Fixed in 0.51.468 Patch available CNA

Remediation

  • Fix · CNA hermes-webui (nesquena) Fixed in 0.51.468

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-55205
  2. 2026-10-03 Alias added: GHSA-hq7f-wv7c-w9mp

References

Patch 3

Other 1

  • TI-2026-36807 Hermes WebUI < 0.51.358 Unauthenticated Password Takeover via /api/settings CVSS 4.0CRITICAL 9.2
  • TI-2026-39878 Hermes WebUI < 0.51.443 - Cross-Profile Session Data Exfiltration via Session Export Endpoint CVSS 4.0HIGH 7.1
  • TI-2026-39877 Hermes WebUI < 0.51.443 - Broken Access Control in /api/session Endpoint CVSS 4.0HIGH 7.1
  • TI-2026-36799 Hermes WebUI < 0.51.269 Profile Isolation Bypass via sessions search CVSS 4.0HIGH 7.1
  • TI-2026-09773 Hermes WebUI before 0.51.221 Path Traversal via Symlink Workspace Bypass CVSS 4.0HIGH 7.1
  • TI-2026-41892 Hermes WebUI < 0.51.521 - Cross-Profile Authorization Bypass via Unset Session Profile on Import CVSS 4.0MEDIUM 6.0
See all 16 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences