CVE-2026-55370 — Logto: TOTP code can be replayed within the RFC 6238 validity window (one-time use violation)
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…
Published: 2026-07-10 · CVSS: 6.4 · CVSS 3.1
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7