CVE-2026-55370CWE-294

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

Medium · published July 10, 2026

CVSS v3.1
6.4
EPSS
0%
Percentile
25.7
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
6.4 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N
CVSS v4.0
Not supplied
EPSS
0.00336 · 25.7th percentile
Weakness
CWE-294 · Authentication Bypass by Capture-replay
Published
2026-07-10T19:56Z
EPSS history
Timeline
  • 10 JUL 19:56Z
    Logto: TOTP code can be replayed within the RFC 6238 validity window (one-time use violation)
    cvelistv5