CVE-2026-84428
- Source
- https://cve.org/CVERecord?id=CVE-2026-84428
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-84428.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2026-84428
- Aliases
-
- GHSA-9q9j-q6p8-xq58
- Published
- 2026-09-04T10:24:27Z
- Modified
- 2026-09-10T03:30:19Z
- 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 header validation bypass via incomplete schema case normalization
- Details
-
fastify versions before 5.12.2 implement the case-insensitive nature of HTTP header names by lowercasing names in a route's header schema before compiling it, but the transformation is incomplete: it lowercases the properties keys and the root-level required array, and does not lowercase the trigger and dependent names inside the JSON Schema Draft 7 dependencies keyword. Because Node stores request header names in lowercase, a canonical-case dependency such as requiring an authentication header whenever a privileged-mode header is present never matches, and the presence assertion is silently skipped. An unauthenticated remote client can therefore send the header that activates a privileged branch while omitting the header the dependency was meant to require, bypassing the conditional check. Users should upgrade to fastify 5.12.2 or later.
- Database specific
{ "cna_assigner": "openjs", "cwe_ids": [ "CWE-178" ], "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/84xxx/CVE-2026-84428.json" }- References