CVE-2026-25223

EUVD-2026-5157
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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
7.5 HIGH
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
GitHub_MCNA
7.5 HIGH
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: 3%
Affected Products (NVD)
VendorProductVersion
fastifyfastify
𝑥
< 5.7.2
𝑥
= Vulnerable software versions
Common Weakness Enumeration
References
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