CVE-2021-39307 json
PDFTron's WebViewer UI 8.0 or below renders dangerous URLs as hyperlinks in supported documents, including JavaScript URLs, allowing the ex…
published 2021-09-15 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-25668
- cvss
- 6.1
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.1%
- EPSS 1.1% chance of exploitation in 30 days, percentile 66%
- public exploits
- 0
- none known
Summary
PDFTron's WebViewer UI 8.0 or below renders dangerous URLs as hyperlinks in supported documents, including JavaScript URLs, allowing the execution of arbitrary JavaScript code.
Patch / fix
Exploit prediction
1.12% chance of exploitation in the next 30 days, higher than 66% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- research.nccgroup.com https://research.nccgroup.com/2021/09/14/technical-advisory-pdftron-javascript-urls-allowed-in-webviewer-ui-cve-2021-39307/ referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
| NVD | 2.0 | 4.3 | AV:N/AC:M/Au:N/C:N/I:P/A:N |
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
References
-
research.nccgroup.com
/2021/09/14/technical-advisory-pdftron-javascript-urls-allowed-in-webviewer-ui-cve-2021-39307/
exploit, patch, third-party-advisory
-
pdftron.com
/webviewer/
product, vendor-advisory
Sources
- CVE List CVE-2021-39307
- NVD CVE-2021-39307
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.