What is the CVSS score of CVE-2026-26717?

CVE-2026-26717 has a CVSS 3.1 base score of 4.8 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N. EPSS exploitation probability: 0.1%.

Which versions of OpenFUN Richie are affected by CVE-2026-26717?

CVE-2026-26717 presents moderate security risk rated CVSS 4.8. Exploitation could compromise the security of affected deployments.. A patch is available.

How to fix or mitigate CVE-2026-26717?

Within 30 days: Identify affected systems and apply vendor patches as part of regular patch cycle. Monitor vendor channels for patch availability.

OpenFUN Richie CVE-2026-26717

MEDIUM

Observable Timing Discrepancy (CWE-208)

2026-02-25 cve@mitre.org

GHSA-xjhr-fm27-4hmx

Authentication Bypass

4.8

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

4.8 MEDIUM

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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

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

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

Low

Availability

None

Lifecycle Timeline

Patch released

Mar 31, 2026 - 21:13 nvd

Patch available

Analysis Generated

Mar 12, 2026 - 21:55 vuln.today

CVE Published

Feb 25, 2026 - 17:25 nvd

MEDIUM 4.8

DescriptionCVE.org

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

AnalysisAI

OpenFUN Richie LMS's course synchronization API uses non-constant-time comparison for HMAC signature validation, allowing remote attackers to forge valid signatures through timing analysis and bypass authentication controls. This vulnerability affects the sync_course_run_from_request function and requires no user interaction, though successful exploitation demands careful timing measurements. No patch is currently available for this medium-severity issue.

Technical ContextAI

exists in the sync_course_run_from_request component. 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