Auth bypass in Logto-Io Logto
CVE-2026-55377
Logto is the modern, open-source auth infrastructure for SaaS and AI apps. Prior to 1.41.0, Logto's Account Center step-up check accepted any active verification record that belonged to the current user and had isVerified === true. A WebAuthn registration verification record for binding a new passkey could be created and verified with only an existing Account API bearer token, then sent in the logto-verification-id header and treated as identityVerified=true by Account Center routes, allowing MFA factor management without proving possession of an existing password, identifier, or MFA factor. This issue is fixed in version 1.41.0.
Vulnerability class: Broken Authentication
EPSS: 0.005 (38.1th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N.
Affected products
- Logto-io Logto — versions < 1.41.0
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-55377?
- CVE-2026-55377 is a high-severity vulnerability in Logto-Io Logto, classified under Improper Authentication. CVSS score: 8.1/10. Published 2026-07-10.
- How severe is CVE-2026-55377?
- High severity. CVSS v3 base score is 8.1 out of 10.