OpenFUN Richie Observable Timing Discrepancy in its sync_course_run_from_request function
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 software
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| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Python (PyPI) | richie | < 3.3.0 | 3.3.0 |
References
- https://nvd.nist.gov/vuln/detail/CVE-2026-26717
- https://github.com/openfun/richie/commit/a1b5bbda3403d7debb466c303a32852925fcba5f
- https://github.com/Rickidevs/CVE-2026-26717
- https://github.com/openfun/richie
- https://medium.com/@ordogh/cve-2026-26717-hmac-timing-attack-in-openfun-richie-lms-f04377efe83d?postPublishedType=repub
- https://pypi.org/project/richie
- https://github.com/advisories/GHSA-xjhr-fm27-4hmx
- CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N- Weakness (CWE)
CWE-208- Platform
- Python (PyPI)
- Package
richie- Disclosed
- 25.02.2026
- Updated
- 11.10.2026 15:17
Sources and licenses
OSV / GitHub Advisory Database - PYSEC-2026-3052 - PyPA Advisory Database; CC BY 4.0
OSV / GitHub Advisory Database - GHSA-xjhr-fm27-4hmx - CC BY 4.0
Vulnerability history: richie
All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.
This is the only known vulnerability of this package.
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