CVE-2026-26717

MEDIUM

4.8

Description

An issue in OpenFUN Richie (LMS) in src/richie/apps/courses/api.py. The application used the non-constant time == operator for HMAC signature verification in the sync_course_run_from_request function. This allows remote attackers to forge valid signatures and bypass authentication by measuring response time discrepancies

CVE Details

CVSS v3.1 Score4.8

SeverityMEDIUM

CVSS VectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

Attack VectorNETWORK

ComplexityHIGH

Privileges RequiredNONE

User InteractionNONE

Published2/25/2026

Last Modified2/27/2026

Sourcenvd

Honeypot Sightings0

Weaknesses (CWE)

CWE-208

References

https://github.com/Rickidevs/CVE-2026-26717(cve@mitre.org)

https://github.com/openfun/richie/commit/a1b5bbda3403d7debb466c303a32852925fcba5f(cve@mitre.org)

https://medium.com/@ordogh/cve-2026-26717-hmac-timing-attack-in-openfun-richie-lms-f04377efe83d?postPublishedType=repub(cve@mitre.org)

IOC Correlations

No correlations recorded

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