CVE-2026-55196 json
Hermes WebUI < 0.51.409 - Unauthenticated Passkey Registration via Authentication Bypass
published 4mo ago modified last mo. also EUVD-2026-37777
- cvss
- 9.1
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.6%
- EPSS 0.6% chance of exploitation in 30 days, percentile 48%
- public exploits
- 0
- none known
Summary
Hermes WebUI before 0.51.409 contains an authentication bypass vulnerability in passkey registration endpoints that allows unauthenticated remote attackers to register arbitrary passkeys. When HERMES_WEBUI_PASSKEY=1 is enabled with no existing credentials, POST /api/auth/passkey/register/options and POST /api/auth/passkey/register endpoints are accessible without authentication, allowing attackers to claim the first passkey and gain permanent administrative control.
Patch / fix
- hermes-webui hermes-webui 0.51.409
- github.com/nesquena/hermes-webui@4d90577 commit
- github.com/nesquena/hermes-webui#4171 pull request
- github.com/nesquena/hermes-webui#4267 pull request
- github.com/nesquena/hermes-webui/releases/tag/v0.51.442 release
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Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- total
- Assessed
- 4mo ago
Exploit prediction
0.58% chance of exploitation in the next 30 days, higher than 48% of all scored CVEs (FIRST EPSS, 2026-11-11).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 9.1 | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N |
| CNA | 3.1 | 9.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N |
| CNA | 4.0 | 9.1 | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
Affected products
- hermes-webui hermes-webui
Classification
- Weakness
-
- CWE-306 Missing Authentication for Critical Functionality
References
-
github.com
/nesquena/hermes-webui/pull/4171
issue-tracking, patch
-
github.com
/nesquena/hermes-webui/pull/4267
issue-tracking, patch
-
github.com
/nesquena/hermes-webui/commit/4d90577e25d5537cb07290eca3fb8abff3bab316
patch
-
github.com
/nesquena/hermes-webui/releases/tag/v0.51.442
release-notes
-
vulncheck.com
/advisories/hermes-webui-unauthenticated-passkey-registration-via-authentication-bypass
third-party-advisory
Sources
- CVE List CVE-2026-55196
- NVD CVE-2026-55196
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.