CVE-2026-33806

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 v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://cna.openjsf.org/security-advisories.html	Vendor Advisory
https://github.com/fastify/fastify/security/advisories/GHSA-mg2h-6x62-wpwc	Not Applicable
https://access.redhat.com/security/cve/CVE-2026-33806
https://bugzilla.redhat.com/show_bug.cgi?id=2458596
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33806.json

Configurations

Configuration 1 (hide)

cpe:2.3:a:fastify:fastify:*:*:*:*:*:node.js:*:*

History

No history.

Information

Published : 2026-04-15 04:17

Updated : 2026-07-15 02:20

NVD link : CVE-2026-33806

Mitre link : CVE-2026-33806

CVE.ORG link : CVE-2026-33806

JSON object : View

Products Affected

fastify

fastify

CWE

CWE-1287

Improper Validation of Specified Type of Input

CWE-1289

Improper Validation of Unsafe Equivalence in Input

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The body is still parsed correctly but schema validation is skipped.\n\nThis is a regression introduced in fastify >= 5.3.2 by the fix for CVE-2025-32442\n\nPatches:\n\nUpgrade to fastify v5.8.5 or later.\n\nWorkarounds:\n\nNone. Upgrade to the patched version."}], "lastModified": "2026-07-15T02:20:15.760", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:fastify:fastify:*:*:*:*:*:node.js:*:*", "vulnerable": true, "matchCriteriaId": "F05DA184-C206-4A06-A5BA-97FBB69A274F", "versionEndExcluding": "5.8.5", "versionStartIncluding": "5.3.2"}], "operator": "OR"}]}], "sourceIdentifier": "ce714d77-add3-4f53-aff5-83d477b104bb"}