Improper Encoding or Escaping of Output in fast-uri - CVE-2026-84292
Published: September 2, 2026
Vulnerability identifier: #VU146816
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-84292
CWE-ID: CWE-116
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to redirect URI authority to an attacker-controlled host.
The vulnerability exists due to improper encoding or escaping of output in the authority recomposition logic when serializing a URI with an unvalidated port component. A remote attacker can supply a non-digit port value containing authority delimiters to redirect URI authority to an attacker-controlled host.
The issue is reachable through the object forms of serialize(), normalize(), and equal(). A port value obtained from parse() is always digits and is not affected.
Affected software
fast-uri
How to mitigate CVE-2026-84292
Install security update from vendor's website.
fast-uri - addressed in versions 2.4.6, 3.1.7, 4.1.4