CVE-2026-26717

Published: Feb 25, 2026Modified: Feb 27, 2026

4.8

Vector

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

Exploitability: 2.2 / Impact: 2.5

Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Secondary)

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

Related CWEs

CWE-208

Observable Timing Discrepancy

Two separate operations in a product require different amounts of time to complete, in a way that is observable to an actor and reveals security-relevant information about the state of the product, such as whether a particular operation was successful or not.

References (3)

https://github.com/Rickidevs/CVE-2026-26717

Source: cve@mitre.org

https://github.com/openfun/richie/commit/a1b5bbda3403d7debb466c303a32852925fcba5f

Source: cve@mitre.org

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

Source: cve@mitre.org

Timeline

No history available yet.