synced 8 MIN AGO
01 Record

CVE-2026-26717

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.

MediumPUBLISHEDCNA: mitre
CNA base score4.8 CVSS v3.xCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

02 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.

03 Exploitation and scoring

Exploitation
Public exploit code exists. CISA's assessment records a public proof of concept. That is not a report of exploitation in the wild.
SSVC decision
  • ExploitationpocPublic proof-of-concept exploit code exists. Not a report of exploitation in the wild.
  • AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
  • Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.
EPSS probability
0.44% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 37.9% of scored records. A rank, not a probability.
NVD base score
4.8 (CVSS v3.x), scored by the NVD independently of the CNA.
NVD CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
NVD analysis status
Deferred. NVD last modified this record on 2026-06-17.
Red Hat severity
No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published
2026-02-25 00:00Z8 MO AGO
Last updated
2026-02-26 19:11Z8 MO AGO
Reserved
2026-02-16
Assigning CNA
mitre
Record state
PUBLISHED
Severity
Medium (CVSS 4.8)
CNA CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
Weaknesses
  • CWE-208Observable Timing DiscrepancyBase
Data version
5.2
Document digest
73dcd7a4002fd5cb50a19d944526783de0713e26d92f281c6ef33330bb5cff62

05 Affected products

No products listed

This record names no affected vendor or product. That is common for reserved identifiers and for records whose CNA published only a narrative description.

06 References