CVE-2026-54733
moodle-local_o365: Authentication bypass via unverified JWT signature in Teams SSO endpoint
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 4.5.6, 5.0.5, 5.1.1
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
CISA's decision points: whether it is exploited, whether attacks can be automated, and how much control an attacker gets. Assessed (SSVC 2.0.3).What do these mean? →
- Exploitation: none
- Automatable: yes
- Technical impact: total
Summary
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.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: yes · Technical impact: total
- Record last updated
Affected versions
- microsoft o365-moodle
fixed in 4.5.6; From 5.0.0 · fixed in 5.0.5; From 5.1.0 · fixed in 5.1.1