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.
History

Wed, 04 Feb 2026 22:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 04 Feb 2026 12:15:00 +0000

Type Values Removed Values Added
First Time appeared Fastify
Fastify fastify
Weaknesses CWE-179
Vendors & Products Fastify
Fastify fastify
References
Metrics threat_severity

None

threat_severity

Important


Tue, 03 Feb 2026 21:45:00 +0000

Type Values Removed Values Added
Description 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.
Title Fastify's Content-Type header tab character allows body validation bypass
Weaknesses CWE-436
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-02-04T21:18:16.693Z

Reserved: 2026-01-30T14:44:47.327Z

Link: CVE-2026-25223

cve-icon Vulnrichment

Updated: 2026-02-04T21:18:14.142Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-02-03T22:16:31.130

Modified: 2026-02-04T16:33:44.537

Link: CVE-2026-25223

cve-icon Redhat

Severity : Important

Publid Date: 2026-02-03T21:21:40Z

Links: CVE-2026-25223 - Bugzilla