CVE-2026-33806

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Source
https://cve.org/CVERecord?id=CVE-2026-33806
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-33806.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2026-33806
Aliases
Downstream
Published
2026-04-15T00:14:02Z
Modified
2026-10-22T10:31:47Z
Severity
  • 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N CVSS Calculator
Summary
fastify vulnerable to Body Schema Validation Bypass via Leading Space in Content-Type Header
Details

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.

Database specific 
{
    "cna_assigner": "openjs",
    "cwe_ids": [
        "CWE-1287"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33806.json"
}
References

Affected packages

Git / github.com/fastify/fastify

Affected ranges

Type
GIT
Repo
https://github.com/fastify/fastify
Events
Introduced
32f7e1eb97b638bad3ff8b80948e5b2c07d1b8b5
Fixed
3983cce8124714242099e8756a7a9a80a0ba0aea
Database specific
Show details 
{
    "extracted_events": [
        {
            "range": [
                {
                    "introduced": "5.3.2"
                },
                {
                    "fixed": "5.8.5"
                }
            ],
            "source": "AFFECTED_FIELD",
            "strategy": "StandardRange"
        },
        {
            "cpe": "cpe:2.3:a:fastify:fastify:*:*:*:*:*:node.js:*:*",
            "range": [
                {
                    "introduced": "5.3.2"
                },
                {
                    "fixed": "5.8.5"
                }
            ],
            "source": "CPE_RANGE"
        }
    ]
}

Affected versions

v5.*
v5.3.2
v5.3.3
v5.4.0
v5.5.0
v5.6.0
v5.6.1
v5.6.2
v5.7.0
v5.7.1
v5.7.2
v5.7.3
v5.7.4
v5.8.0
v5.8.1
v5.8.2
v5.8.3
v5.8.4

Database specific

source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-33806.json"