CVE-2026-54733
moodle-local_o365: Authentication bypass via unverified JWT signature in Teams SSO endpoint
CVSS Score
0.0
EPSS Score
0.0%
EPSS Percentile
0th
The Microsoft 365 and Microsoft Entra ID Plugins for Moodle provide Office 365 and Azure Active Directory integration for Moodle. Prior to 4.5.6, 5.0.5, and 5.1.1, the Microsoft Office 365 Integration plugin local_o365 Teams SSO endpoint sso_login.php base64-decodes a JWT payload and authenticates users from the upn claim without verifying the JWT signature, allowing an unauthenticated attacker to forge a token and obtain a Moodle session as an O365-authenticated user. This issue is fixed in versions 4.5.6, 5.0.5, and 5.1.1.
| CWE | CWE-347 |
| Vendor | microsoft |
| Product | o365-moodle |
| Ecosystems | |
| Industries | TechnologyEnterprise |
| Published | Jul 16, 2026 |
| Last Updated | Jul 16, 2026 |
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Affected Versions
microsoft / o365-moodle
< 4.5.6 >= 5.0.0, < 5.0.5 >= 5.1.0, < 5.1.1
References
github.com: https://github.com/microsoft/o365-moodle/security/advisories/GHSA-hqjh-93qv-47v5 github.com: https://github.com/microsoft/o365-moodle/commit/01b2d4c2e13b06a66557527084cbf9bace655944 github.com: https://github.com/microsoft/o365-moodle/commit/258872f6e2011f4efa8ebb77d2898142a9435e89 github.com: https://github.com/microsoft/o365-moodle/commit/d5596655f0baaee0f11aec2e10d6f36b0bd29220 github.com: https://github.com/microsoft/o365-moodle/releases/tag/v20260423_m405 github.com: https://github.com/microsoft/o365-moodle/releases/tag/v20260423_m500 github.com: https://github.com/microsoft/o365-moodle/releases/tag/v20260423_m501