CVE-2025-66520: pdfonline.foxit.com · XSS or 'Cross-site Scripting'
Affects pdfonline.foxit.comSource CVE Database V5
Not known to be exploited · CVSS 6.3 Medium.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:L/A:NExploitation evidence
Disclosed: evidence found.
CVE published 19 Dec 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
AI-suggested
- Apply any available patches or updates from Foxit Software Inc. promptly once released to address this vulnerability.
- Until patches are available, restrict or monitor the upload of SVG files within the Portfolio feature, possibly disabling SVG support if feasible.
- Implement Content Security Policy (CSP) headers to limit the execution of unauthorized scripts in browsers accessing the service.
- Educate users about the risks of interacting with untrusted Portfolio files and encourage cautious behavior when opening files from unknown sources.
- Employ web application firewalls (WAFs) with custom rules to detect and block malicious SVG payloads or suspicious script injections targeting the affected service.
- Monitor logs and user activity for unusual behavior indicative of exploitation attempts.
- Coordinate with Foxit support to receive timely updates and guidance.
- Consider isolating access to the cloud PDF editor from sensitive internal networks or using secure browser environments to reduce risk.
Description
A stored cross-site scripting (XSS) vulnerability exists in the Portfolio feature of the Foxit PDF Editor cloud (pdfonline.foxit.com). User-supplied SVG files are not properly sanitized or validated before being inserted into the HTML structure. As a result, embedded HTML or JavaScript within a crafted SVG may execute whenever the Portfolio file list is rendered.