CVE-2026-2345Insufficient Origin Validation in Proctorio Chrome Extension postMessage Handlers
- 3.6LowCVSS base score
- 0.08%Exploitation in 30 daysEPSS · top 100% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
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.
Timeline
ID reserved
By Hackrate
Published
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| HackrateCNA (assigner) | 3.1 | Low3.6 | CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N |
| NVDNVD · Deferred | 3.1 | Low3.6 | CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N |
- EPSS (exploitation in 30 days)
- 0.08% · top 100% of all CVEs (13 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Low 3.6.
Affected products
Proctorio · Secure Exam Proctor Extension
- affected 1.5.25220.33
- unaffected 1.5.25220.36
References
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-6252 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-2345)Record last updated .