CVE-2025-66500: webplugins.foxit.com · XSS or 'Cross-site Scripting'
Affects webplugins.foxit.comSource CVE Database V5
Not known to be exploited · CVSS 6.3 Medium.
Data as of 26 Oct 2026, 10:12 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 10% 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
European organizations should immediately verify their use of Foxit webplugins.foxit.com and identify affected versions prior to December 1, 2025. This includes enforcing a whitelist of trusted origins and sanitizing all inputs assigned to script sources. Additionally, applying Content Security Policy (CSP) headers can help restrict script execution to trusted domains, mitigating the impact of injected scripts. Monitoring web traffic for unusual postMessage activity and educating users about the risks of interacting with untrusted web content can further reduce exposure. Organizations should stay alert for official patches or updates from Foxit and apply them promptly once available. Finally, conducting regular security assessments and penetration testing focused on web plugin integrations will help identify and remediate similar vulnerabilities.
Description
A stored cross-site scripting (XSS) vulnerability exists in webplugins.foxit.com. A postMessage handler fails to validate the message origin and directly assigns externalPath to a script source, allowing an attacker to execute arbitrary JavaScript when a crafted postMessage is received.