GHSA-XJHR-FM27-4HMX
Vulnerability from github – Published: 2026-02-25 18:31 – Updated: 2026-02-26 22:50An 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.
{
"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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