CVE-2026-26717
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
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
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
- Record
CVE-2026-26717- CVSS 3.1
- 4.8 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-208
- Updated
- 2026-11-02
EUVDEUVD-2026-8680
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
- Record
EUVD-2026-8680- CVSS 3.1
- 4.8 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-xjhr-fm27-4hmx
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.
- Record
GHSA-xjhr-fm27-4hmx- CVSS 3.1
- 4.8 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-208
- Updated
- 2026-11-02
NVD
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
- Record
CVE-2026-26717- CVSS 3.1
- 4.8 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-208
- Updated
- 2026-11-02
OSV
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
- Record
CVE-2026-26717- CVSS 3.1
- 4.8 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N - Updated
- 2026-11-02
OSVGHSA-xjhr-fm27-4hmx
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.
- Record
GHSA-xjhr-fm27-4hmx- CVSS 3.1
- 4.8 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-208
- Updated
- 2026-11-02
OSVPYSEC-2026-3052
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.
- Record
PYSEC-2026-3052- CVSS 3.1
- 4.8 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N - Updated
- 2026-11-02
Affected packages
| Package | Affected | Fixed |
|---|---|---|
richiePyPI | before 3.3.0 | 3.3.0 |
richiePyPI | before 3.3.0, plus listed versions 0.1.01.0.01.0.0b01.0.0b11.0.0b2 Show 45 moreShow less1.0.0b31.0.0b41.0.0b51.0.0b61.0.0b71.0.0b81.0.0b91.0.11.1.01.10.01.11.01.12.01.12.11.13.01.14.01.14.11.15.01.16.01.16.11.16.21.17.01.2.01.3.01.4.01.4.11.5.01.5.11.5.21.6.01.6.11.7.01.7.11.7.21.7.31.8.01.8.11.8.21.8.31.9.01.9.11.9.22.0.02.0.0b02.0.0b12.0.0b11 | 3.3.0 |
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| PoC in GitHub | Rickidevs/CVE-2026-26717 | 2026-02-24 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV, PoC in GitHub |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-26717 is a medium vulnerability (CVSS 4.8) in richie, published February 25, 2026. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 0.44%, the 38th percentile. Fixed in richie 3.3.0.
References
github.com/openfun/richie/commit/a1b5bbda3403d7debb466c303a32852925fcba5f
medium.com/@ordogh/cve-2026-26717-hmac-timing-attack-in-openfun-richie-lms-f04377efe83d?postPublishedType=repub
nvd.nist.gov/vuln/detail/CVE-2026-26717
pypi.org/project/richie
Left out here: 77 versions. The JSON record has them.