CVE-2026-26717

MEDIUM EPSS 29.4%
Published Feb 25, 20264mo ago · Modified Apr 15, 20262mo ago
4.8 CVSS 3.1
Medium
Find Similar
Published Feb 25, 2026 4mo ago
Last Modified Apr 15, 2026 2mo ago

Description

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

CVSS Details

Base Score
4.8
Exploitability
2.2
Impact
2.5
Vector string
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

Threat Intelligence

EPSS Exploit Probability
29.4% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 1

CWE-208

References 3

  • github.com https://github.com/Rickidevs/CVE-2026-26717
  • github.com https://github.com/openfun/richie/commit/a1b5bbda3403d7debb466c303a32852925fcba5f
  • medium.com https://medium.com/@ordogh/cve-2026-26717-hmac-timing-attack-in-openfun-richie-lms-f04377efe83d?postPublishedType=repub

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.