SB2026020389 - Spoofing attack in Fastify 



SB2026020389 - Spoofing attack in Fastify

Published: February 3, 2026

Security Bulletin ID SB2026020389
Severity
Medium
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Data manipulation

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 security vulnerability.


1) Interpretation conflict (CVE-ID: CVE-2026-25223)

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 update from vendor's website.