CVE-2026-55370 MEDIUM

CVE-2026-55370: Logto: TOTP code can be replayed within the RFC 6238 validity window (one-time use violation)

Vendor Logto-Io
Product logto
Weakness CWE-294
Published July 10, 2026
Last update July 10, 2026
View on NVD All CVEs

CVSS base score

6.4/10
Attack vector Network
Attack complexity High
Privileges required Low
User interaction Required
Confidentiality High
Integrity High

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N

What the vulnerability does

01Description

Logto is the modern, open-source auth infrastructure for SaaS and AI apps. Prior to 1.41.0, Logto's existing TOTP verification accepted a successfully used TOTP code again while the code remained inside the RFC 6238 acceptance window because the verifier used otplib's stateless check with window = 1 and did not persist or compare the accepted TOTP time-step counter. An attacker who has the victim's first factor and captures a live TOTP value can replay that value to satisfy MFA during the same acceptance window. This issue is fixed in version 1.41.0.

Key dates

02Disclosure timeline

July 10, 2026 CVE published