GHSA-XJHR-FM27-4HMX

Vulnerability from github – Published: 2026-02-25 18:31 – Updated: 2026-02-26 22:50
VLAI?
Summary
OpenFUN Richie Observable Timing Discrepancy in its sync_course_run_from_request function
Details

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.

Severity ?
4.8 (Medium)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
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{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "richie"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.3.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-26717"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-208"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-02-26T22:50:20Z",
    "nvd_published_at": "2026-02-25T17:25:39Z",
    "severity": "MODERATE"
  },
  "details": "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.",
  "id": "GHSA-xjhr-fm27-4hmx",
  "modified": "2026-02-26T22:50:20Z",
  "published": "2026-02-25T18:31:38Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-26717"
    },
    {
      "type": "WEB",
      "url": "https://github.com/openfun/richie/commit/a1b5bbda3403d7debb466c303a32852925fcba5f"
    },
    {
      "type": "WEB",
      "url": "https://github.com/Rickidevs/CVE-2026-26717"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/openfun/richie"
    },
    {
      "type": "WEB",
      "url": "https://medium.com/@ordogh/cve-2026-26717-hmac-timing-attack-in-openfun-richie-lms-f04377efe83d?postPublishedType=repub"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "OpenFUN Richie Observable Timing Discrepancy in its sync_course_run_from_request function"
}


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