CVE-2026-55205

EUVD-2026-37904
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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
5.3 MEDIUM
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Awaiting analysis
This vulnerability is currently awaiting analysis.
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Common Weakness Enumeration
References
https://github.com/nesquena/hermes-webui/commit/ce272d9cd5f8e5a4521278f56eb5388010901646
https://github.com/nesquena/hermes-webui/pull/3970
https://github.com/nesquena/hermes-webui/pull/4338
https://github.com/nesquena/hermes-webui/releases/tag/v0.51.468
https://www.vulncheck.com/advisories/hermes-webui-resource-exhaustion-via-unauthenticated-oauth-flow-endpoint
https://github.com/nesquena/hermes-webui/pull/3970