Unauthenticated middleware bypass via HEAD request
Published Mar 20, 2026 · Updated Mar 20, 2026
Authorization bypass in Nest before 11.1.16 allows remote attackers to execute GET handlers without configured middleware via HEAD requests. The middleware request-method check treated HEAD only as HEAD and called next() instead of the GET middleware proxy, while Fastify forwarded HEAD to GET. Exposure requires @nestjs/platform-fastify with GET-scoped middleware; bypassed authorization or validation permits unintended handler effects even though the HEAD response has no body.
Summary
What happened
Authorization bypass in Nest before 11.1.16 allows remote attackers to execute GET handlers without configured middleware via HEAD requests. The middleware request-method check treated HEAD only as HEAD and called next() instead of the GET middleware proxy, while Fastify forwarded HEAD to GET. Exposure requires @nestjs/platform-fastify with GET-scoped middleware; bypassed authorization or validation permits unintended handler effects even though the HEAD response has no body.
The record
- CVE
- CVE-2026-33011
- Published
- Mar 20, 2026
- Updated
- Mar 20, 2026
- Vendor
- NestJS
- Product
- Nest
- Classifications
- CWE-670, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 20, 2026CVE publishedPublication date reported by the CVE source.
- Mar 20, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=< 11.1.16
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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