Critical 9.3Published Jul 16, 2026

CVE-2026-54733moodle-local_o365: Authentication bypass via unverified JWT signature in Teams SSO endpoint

Updated under an hour ago (Oct 27, 2026, 4:10 PM ET)

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It affects microsoft o365-moodle. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for microsoft o365-moodle

Exploited in the last 30 days

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.

CVSS: 9.3 CRITICAL (v4.0, CNA)CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Weakness (CWE): CWE-347
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Awaiting Analysis
Record last updated: Jul 16, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

microsoft o365-moodle microsoft:o365_moodle (from the name)	before 4.5.6; from 5.0.0, < 5.0.5; from 5.1.0, < 5.1.1	CNA record

References

References

https://github.com/microsoft/o365-moodle/security/advisories/GHSA-hqjh-93qv-47v5	x-refsource-confirm
https://github.com/microsoft/o365-moodle/commit/01b2d4c2e13b06a66557527084cbf9bace655944	x-refsource-misc
https://github.com/microsoft/o365-moodle/commit/258872f6e2011f4efa8ebb77d2898142a9435e89	x-refsource-misc
https://github.com/microsoft/o365-moodle/commit/d5596655f0baaee0f11aec2e10d6f36b0bd29220	x-refsource-misc
https://github.com/microsoft/o365-moodle/releases/tag/v20260423_m405	x-refsource-misc
https://github.com/microsoft/o365-moodle/releases/tag/v20260423_m500	x-refsource-misc
https://github.com/microsoft/o365-moodle/releases/tag/v20260423_m501	x-refsource-misc

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.