by Kastro
Paper/Archive/CVE-2026-58122

CVE-2026-58122

nesquena hermes-webui — Hermes WebUI < 0.51.307 Authentication Bypass via X-Forwarded-For Header Spoofing

EPSS 0.4%CVSS 9.3
critical.is priorityof 100
34
CVSS 9.3 (CNA)9.3 / 10 × 3027.9Not in CISA KEV+300.0EPSS percentile 31.2.312 × 206.2No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

Hermes WebUI before 0.51.307 contains an authentication bypass vulnerability that allows unauthenticated remote attackers to circumvent local-origin IP restrictions on onboarding endpoints by supplying a spoofed X-Forwarded-For header with a loopback address. Attackers can exploit this bypass to perform server-side request forgery against internal services including cloud metadata endpoints, overwrite LLM provider configuration and API keys with attacker-controlled values, or initiate OAuth device-code flows to obtain persistent access tokens stored in auth.json.

Affected

ProductAffectedFixed inSource
hermes-webui< 0.51.3070.51.307CNA

Scores by source

VulnCheck (CNA)9.3CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
VulnCheck (CNA)9.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CISA ADPSSVCExploitation: none · Automatable: yes · Technical impact: total

References

refgithub.com/nesquena/hermes-webui/releases/tag/v0.51.307refgithub.com/nesquena/hermes-webui/pull/3758patchgithub.com/nesquena/hermes-webui/commit/70596e6993be0d4cee083c1c1a86f5e7ad5d57b7writeupvulncheck.com/advisories/hermes-webui-authentication-bypass-via-x-forwarded-for-header-spoofing