SB20261106105 - Multiple vulnerabilities in Fastify

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Main Vulnerability Database SB20261106105

SB20261106105 - Multiple vulnerabilities in Fastify

Published: November 6, 2026

Security Bulletin ID SB20261106105
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Data manipulation

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Improper Handling of Case Sensitivity (CVE-ID: CVE-2026-107832)

CWE-ID: CWE-178 - Improper Handling of Case Sensitivity

CVSSv4: 6.3 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]


The vulnerability allows an unauthenticated remote attacker to bypass request header restrictions and pass forbidden headers to Fastify handlers.

The vulnerability exists due to incomplete case normalization in Fastify header schema validation when applications use mixed-case header names in enum or const constraints inside a propertyNames deny-list. An unauthenticated remote attacker can send a forbidden header whose lowercased name fails to match the configured restriction.


Remediation

Install update from vendor's website.

References