CVE-2026-25223

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.

The following products are affected by CVE-2026-25223 vulnerability.

Here, you will find a curated list of external links that provide in-depth information to CVE-2026-25223.

URL	Resource
https://fastify.dev/docs/latest/Reference/Validation-and-Serialization
https://github.com/fastify/fastify/blob/759e9787b5669abf953068e42a17bffba7521348/lib/content-type-parser.js#L125
https://github.com/fastify/fastify/blob/759e9787b5669abf953068e42a17bffba7521348/lib/validation.js#L272
https://github.com/fastify/fastify/commit/32d7b6add39ddf082d92579a58bea7018c5ac821
https://github.com/fastify/fastify/security/advisories/GHSA-jx2c-rxcm-jvmq
https://hackerone.com/reports/3464114
https://nvd.nist.gov/vuln/detail/CVE-2026-25223
https://www.cve.org/CVERecord?id=CVE-2026-25223