Cross-site scripting in fast-uri - CVE-2026-110725
Published: November 10, 2026
Vulnerability identifier: #VU164380
CSH Severity: Low
CVSS v4: 6.3 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N]
CVE-ID: CVE-2026-110725
CWE-ID: CWE-79
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to inject URI schemes and potentially enable cross-site scripting in applications using fast-uri.
The vulnerability exists due to missing first-segment colon escaping in fast-uri's serialize(), normalize(), and resolve() functions when processing references without an authority using reference: 'suffix'. A remote attacker can supply javascript:alert(1) or references containing data: or vbscript: schemes to make output reparse as an absolute URI when treated as a URL, while equal() can conflate scheme-bearing and relative references.
Affected software
fast-uri
ApplinX
ApplinX
How to mitigate CVE-2026-110725
Install security update from vendor's website.
fast-uri - addressed in versions 2.4.8, 3.1.9, 4.2.3