CVE-2026-55205
MEDIUMHermes WebUI < 0.51.468 - Resource Exhaustion via Unauthenticated OAuth Flow Endpoint
Title source: cnaDescription
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.
References (5)
Core 5
Core References
Release Notes release-notes
Release Notes
https://github.com/nesquena/hermes-webui/releases/tag/v0.51.468
Technical Description technical-description
Researcher Pull Request
https://github.com/nesquena/hermes-webui/pull/3970
Issue Tracking issue-tracking
Maintainer Pull Request
https://github.com/nesquena/hermes-webui/pull/4338
Patch patch
Patch Commit
https://github.com/nesquena/hermes-webui/commit/ce272d9cd5f8e5a4521278f56eb5388010901646
Third Party Advisory third-party-advisory
https://www.vulncheck.com/advisories/hermes-webui-resource-exhaustion-via-unauthenticated-oauth-flow-endpoint
Scores
CVSS v3
5.3
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
CISA SSVC
Vulnrichment
Exploitation
poc
Automatable
yes
Technical Impact
partial
Details
CWE
CWE-770
Status
published
Products (2)
nesquena/hermes-webui
< 0.51.468
nesquena/hermes-webui
0.51.468
Published
Jun 18, 2026
Tracked Since
Jun 18, 2026