#VU122274 Interpretation conflict in Fastify - CVE-2026-25223
Published: February 3, 2026
Vulnerability identifier: #VU122274
Vulnerability risk: Medium
CVSSv4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-25223
CWE-ID: CWE-436
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerable software:
Fastify
Fastify
Software vendor:
fastify.io
fastify.io
Description
The vulnerability allows a remote attacker to perform spoofing attack.
The vulnerability exists due to improper input validation when handling "\t" characters. A remote attacker can bypass body validation checks set by the Content-Type header and perform spoofing attack.
Remediation
Install updates from vendor's website.