An issue in OpenFUN Richie (LMS) in src/richie/apps/courses/api.py.
Priority MEDIUM 55CWE-208Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- Information disclosure
- Confidentiality · integrity · availability
- Low · Low · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and GitHub. Impact type from CWE-208.
Summary
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
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.0044 38th percentileScored 2026-11-07
Fix Fixed richie (PyPI): 3.3.0
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
| — | richie (PyPI) | before 3.3.0 | 3.3.0 | Patch available | GHSA-xjhr-fm27-4hmx |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
- richie (PyPI) Vendor— Affected before 3.3.0 Fixed in 3.3.0 Patch available GHSA-xjhr-fm27-4hmx
Remediation
- Fix · GHSA-xjhr-fm27-4hmx richie (PyPI) Fixed in 3.3.0 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-26717
- 2026-10-03 Alias added: GHSA-xjhr-fm27-4hmx
References
Sources
- CVE-2026-26717 · CVE Program
- CVE-2026-26717 · NVD
- FIRST EPSS
- GHSA-xjhr-fm27-4hmx · GitHub Advisory Database · CC BY 4.0
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