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CVE-2026-2345

Insufficient Origin Validation in Proctorio Chrome Extension postMessage Handlers

CVSS 3.6 LOWEPSS 0.1%CWE-346
Vexday Risk Score
8Low
SSVC decision (CISA)
Track
No exploitation signal → monitor
CVSS 3.6EPSS 0.1%KEV nãoPoC Nuclei Metasploit Patch
Lifecycle
11 Feb 2026Published on NVD
Recommendation: Monitor — no exploitation signal at the moment.
Proctorio Chrome Extension is a browser extension used for online proctoring. The extension contains multiple window.addEventListener('message', ...) handlers that do not properly validate the origin of incoming messages. Specifically, an internal messaging bridge processes messages based solely on the presence of a fromWebsite property without verifying the event.origin attribute.
CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N

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