VulnerabilityDeferred

CVE-2026-55370

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.

MEDIUM 6.4EPSS 0.34%

Does this matter?

Lower severity and a low EPSS score (0.34%). Track it; it rarely justifies an emergency change on its own.

Description

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.

CVSS 3.1: 6.4 MEDIUMCVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N
EPSS: 0.34% probability · 27th percentile
CISA KEV: Not listed
Weakness: CWE-294
Source: security-advisories@github.com

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.