CVE-2026-49955
Hermes WebUI before version 0.51.270 contains a resource exhaustion vulnerability that allows unauthenticated remote attackers to degrade service availability by repeatedly calling the passkey options endpoint without completing assertion.
Does this matter?
Lower severity and a low EPSS score (0.59%). Track it; it rarely justifies an emergency change on its own.
Description
Hermes WebUI before version 0.51.270 contains a resource exhaustion vulnerability that allows unauthenticated remote attackers to degrade service availability by repeatedly calling the passkey options endpoint without completing assertion. Attackers can send unlimited POST requests to the authentication endpoint, causing unbounded growth of the challenge store file and excessive CPU and disk I/O through repeated JSON file rewrites.
- CVSS 4.0
- 6.9 MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.59% probability · 46th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-770
- Source
- disclosure@vulncheck.com
References
- https://github.com/nesquena/hermes-webui/commit/58528a4d88b0fa4f7b822e31d6051c669769bd3b
- https://github.com/nesquena/hermes-webui/pull/3624
- https://github.com/nesquena/hermes-webui/pull/3674
- https://github.com/nesquena/hermes-webui/releases/tag/v0.51.270
- https://www.vulncheck.com/advisories/hermes-webui-resource-exhaustion-via-passkey-options
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.