CVE-2026-2345 json
Insufficient Origin Validation in Proctorio Chrome Extension postMessage Handlers
published 2026-02-11 8 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-6252
- cvss
- 3.6
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.1%
- EPSS 0.1% chance of exploitation in 30 days, percentile 0%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- Proctorio Secure Exam Proctor Extension 1.5.25220.36
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 8 mo ago
Exploit prediction
0.08% chance of exploitation in the next 30 days, higher than 0% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 3.6 | CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N |
Affected products
- Proctorio Secure Exam Proctor Extension
Classification
- Weakness
-
- CWE-346 Origin Validation Error
References
Sources
- CVE List CVE-2026-2345
- NVD CVE-2026-2345
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.