CVE-2026-55196
Auth bypass in Hermes WebUI passkey endpoints enables unauthenticated admin takeover.
Is CVE-2026-55196 being exploited?
Not confirmed. CVE-2026-55196 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.58% probability of exploitation in the next 30 days.
How severe is CVE-2026-55196?
CVE-2026-55196 is rated Critical with a CVSS score of 9.1. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-55196?
Yes. A fix has been recorded for CVE-2026-55196. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-55196 affect?
CVE-2026-55196 affects Hermes WebUI < 0.51.409. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-55196?
Upgrade to 0.51.409+; audit and revoke passkeys.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Unauthenticated attackers can register the first passkey and gain permanent admin control via passkey endpoints.
Immediate action required
- affected< 0.51.409
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.