medium4.8
CVE-2026-26717
OpenFUN Richie Observable Timing Discrepancy in its sync_course_run_from_request function
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| pip | richie | < 3.3.0 | 3.3.0 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/Rickidevs/CVE-2026-26717
- https://github.com/openfun/richie/commit/a1b5bbda3403d7debb466c303a32852925fcba5f
- https://medium.com/@ordogh/cve-2026-26717-hmac-timing-attack-in-openfun-richie-lms-f04377efe83d?postPublishedType=repub
- https://github.com/advisories/GHSA-xjhr-fm27-4hmx
- https://nvd.nist.gov/vuln/detail/CVE-2026-26717