CVE-2026-33806 (GCVE-0-2026-33806)
Vulnerability from cvelistv5 – Published: 2026-04-15 00:14 – Updated: 2026-04-15 16:13
VLAI?
Title
fastify vulnerable to Body Schema Validation Bypass via Leading Space in Content-Type Header
Summary
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.
Severity ?
7.5 (High)
CWE
- CWE-1287 - Improper Validation of Specified Type of Input
Assigner
References
Impacted products
Credits
mcollina
climba03003
jsumners
UlisesGascon
Vyntral
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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