---
id: CVE-2026-25223
title: 'Fastify is a fast and low overhead web framework, for Node.js'
summary: >-
  Fastify is a fast and low overhead web framework, for Node.js. Prior to
  version 5.7.2, a validation bypass vulnerability exists in Fastify where
  request body validation schemas specified by Content-Type can be completely
  circumvented. By…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N'
cwe:
  - CWE-436
  - CWE-179
vendor: fastify
product: fastify
affected:
  - fastify < 5.7.2
patched:
  - fastify 5.7.2
published: '2026-02-03'
updated: '2026-06-30'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-25223'
references:
  - url: 'https://fastify.dev/docs/latest/Reference/Validation-and-Serialization'
    label: security-advisories@github.com
  - url: >-
      https://github.com/fastify/fastify/blob/759e9787b5669abf953068e42a17bffba7521348/lib/content-type-parser.js#L125
    label: security-advisories@github.com
  - url: >-
      https://github.com/fastify/fastify/blob/759e9787b5669abf953068e42a17bffba7521348/lib/validation.js#L272
    label: security-advisories@github.com
  - url: >-
      https://github.com/fastify/fastify/commit/32d7b6add39ddf082d92579a58bea7018c5ac821
    label: security-advisories@github.com
  - url: 'https://github.com/fastify/fastify/security/advisories/GHSA-jx2c-rxcm-jvmq'
    label: security-advisories@github.com
  - url: 'https://hackerone.com/reports/3464114'
    label: security-advisories@github.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:10184'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:5807'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:6192'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/security/cve/CVE-2026-25223'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2436560'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-25223.json
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-25223'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-25223'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00818
epssPercentile: 0.55354
ingestedAt: '2026-07-03T18:53:52.164Z'
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-02-04T21:18:10.359742Z'
---

## Overview

Fastify is a fast and low overhead web framework, for Node.js. Prior to version 5.7.2, a validation bypass vulnerability exists in Fastify where request body validation schemas specified by Content-Type can be completely circumvented. By appending a tab character (\t) followed by arbitrary content to the Content-Type header, attackers can bypass body validation while the server still processes the body as the original content type. This issue has been patched in version 5.7.2.

## Affected

- `fastify < 5.7.2`

## Remediation

Upgrade past the affected range:

- `fastify 5.7.2`

## Vendor advisories

- **RHSA-2026:5807** · Red Hat · fixed in: Red Hat OpenShift AI 2.16 · released 2026-03-25 · [advisory](https://access.redhat.com/errata/RHSA-2026:5807)
- **RHSA-2026:10184** · Red Hat · fixed in: Red Hat OpenShift AI 2.25 · released 2026-04-23 · [advisory](https://access.redhat.com/errata/RHSA-2026:10184)
- **RHSA-2026:6192** · Red Hat · fixed in: Red Hat OpenShift Dev Spaces 3.27 · released 2026-03-30 · [advisory](https://access.redhat.com/errata/RHSA-2026:6192)
- **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux AI (RHEL AI) 3, Red Hat OpenShift AI (RHOAI) · no fix planned: Red Hat Enterprise Linux AI (RHEL AI) 3, Red Hat OpenShift AI (RHOAI) · updated 2026-09-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-25223.json)