CVE-2026-33806

Description

Impact: Fastify applications using schema.body.content for per-content-type body validation can have validation bypassed entirely by prepending a space to the Content-Type header. The body is still parsed correctly but schema validation is skipped. This is a regression introduced in fastify >= 5.3.2 by the fix for CVE-2025-32442 Patches: Upgrade to fastify v5.8.5 or later. Workarounds: None. Upgrade to the patched version.

CVSS Vector

References

• https://cna.openjsf.org/security-advisories.html
• https://github.com/fastify/fastify/security/advisories/GHSA-mg2h-6x62-wpwc