Vulnerability in Proctorio Secure Exam Proctor Extension

CVE-2026-2345

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.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 3.6 (Low). Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.001 (0.0th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 0th percentile — 0.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-2345: held from 0.001 to 0.001.

EPSS over last 30 days · oldest: 0.001 · newest: 0.001 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-2345?
CVE-2026-2345 is a low-severity vulnerability in Proctorio Secure Exam Proctor Extension, classified under Origin Validation Error. CVSS score: 3.6/10. Published 2026-02-11.
How severe is CVE-2026-2345?
Low severity. CVSS v3 base score is 3.6 out of 10.