Medium severity · published Jan 20, 2026
CVE-2025-66523
Reflected Cross-Site Scripting (XSS) Vulnerability in na1.foxitesign.foxit.com via Unsanitized URL Parameters
6.1
CVSS
0.2%
EPSS
No
On KEV
Description
URL parameters are directly embedded into JavaScript code or HTML attributes without proper encoding or sanitization. This allows attackers to inject arbitrary scripts when an authenticated user visits a crafted link.
This issue affects na1.foxitesign.foxit.com: before 2026‑01‑16.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 9% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
NA
na1.foxitesign.foxit.com · Foxit Software Inc.
before 2026‑01‑16 · source: vendor
ES
Esign · Foxit
before 2026-01-16 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-66523
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-66523
Vendor Advisory
https://www.foxit.com/support/security-bulletins.html
More from na1.foxitesign.foxit.com
7.1
CVE-2026-4947
Insecure Direct Object Reference (IDOR) Leading to Signature Forgery in Foxit eSign