CVE-2026-55370
MEDIUMLogto: TOTP code can be replayed within the RFC 6238 validity window (one-time use violation)
Title source: cnaDescription
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.
References (4)
Core 4
Core References
X_Refsource_Confirm x_refsource_confirm
https://github.com/logto-io/logto/security/advisories/GHSA-6wj7-c66m-6c82
X_Refsource_Misc x_refsource_misc
https://github.com/logto-io/logto/pull/9109
X_Refsource_Misc x_refsource_misc
https://github.com/logto-io/logto/commit/9118867f6cbadc7291cf913beb4fede91ed5d374
X_Refsource_Misc x_refsource_misc
https://github.com/logto-io/logto/releases/tag/v1.41.0
Scores
CVSS v3
6.4
EPSS
0.0020
EPSS Percentile
10.0%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
total
Details
CWE
CWE-294
Status
published
Products (1)
logto-io/logto
< 1.41.0
Published
Jul 10, 2026
Tracked Since
Jul 11, 2026