CVE-2026-26717

CVSS 4.8 MEDIUMEPSS 0.4%CWE-208

Vexday Risk Score

13Low

SSVC decision (CISA)

Track

No exploitation signal → monitor

CVSS 4.8EPSS 0.4%KEV nãoPoC —Patch —

Lifecycle

25 Feb 2026Published on NVD

Recommendation: Monitor — no exploitation signal at the moment.

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

Affected products

n/a · n/a

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References

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