CVE-2026-55370

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

State
Published
Severity
6.4 Medium
Published
Jul 10, 2026
Updated
Jul 10, 2026
Reserved
Jun 16, 2026

Read the record on cve.org

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.

Scores

CVSSScoreVectorSource
3.16.4 MediumCVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:NGitHub_M

Weaknesses

  • CWE-294 Authentication Bypass by Capture-replay

Affected Products

ProductVersions
logtologto-io
  • < 1.41.0Affected

References

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