CVE-2026-76169

Fastify (versions >= 4.0.0 and

CVE-2026-76169 fastify vulnerable to authentication bypass via malformed URLs reaching encapsulated not-found handlers

fastify versions = 4.0.0 and before 5.12.2 can route a malformed URL sent under one plugin prefix to the custom not-found handler of a different sibling plugin, and invoke it without the preHandler hook declared for that handler. The internal not-found router for encapsulated handlers dispatches...

EUVD-2026-70988

fastify versions = 4.0.0 and before 5.12.2 can route a malformed URL sent under one plugin prefix to the custom not-found handler of a different sibling plugin, and invoke it without the preHandler hook declared for that handler. The internal not-found router for encapsulated handlers dispatches...

CVE-2026-76169 fastify vulnerable to authentication bypass via malformed URLs reaching encapsulated not-found handlers

fastify versions = 4.0.0 and before 5.12.2 can route a malformed URL sent under one plugin prefix to the custom not-found handler of a different sibling plugin, and invoke it without the preHandler hook declared for that handler. The internal not-found router for encapsulated handlers dispatches...

CVE-2026-76169 fastify vulnerable to authentication bypass via malformed URLs reaching encapsulated not-found handlers

fastify versions = 4.0.0 and before 5.12.2 can route a malformed URL sent under one plugin prefix to the custom not-found handler of a different sibling plugin, and invoke it without the preHandler hook declared for that handler. The internal not-found router for encapsulated handlers dispatches...

CVE-2026-84504 fastify vulnerable to request body replacement via an async validation result collision

fastify versions before 5.12.2 treat the object resolved by a successful Ajv async validator as the value result protocol used by custom validator compilers. If a request that passes its route schema contains a property named value at the root, fastify replaces the entire request body with that...

CVE-2026-84504

fastify versions before 5.12.2 are vulnerable to a request body replacement flaw caused by an Ajv async validator result collision. When a request that passes its route schema contains a root-level property named value, fastify treats that property as the value result protocol used by custom vali...

CVE-2026-84504 fastify vulnerable to request body replacement via an async validation result collision

fastify versions before 5.12.2 treat the object resolved by a successful Ajv async validator as the value result protocol used by custom validator compilers. If a request that passes its route schema contains a property named value at the root, fastify replaces the entire request body with that...

Incorrect Behavior Order: Early Validation

Overview fastify is an overhead web framework, for Node.js. Affected versions of this package are vulnerable to Incorrect Behavior Order: Early Validation through the request validation path in lib/validation.js. An attacker can replace the validated request body, or trigger a validation failure,...

@agent-tool-platform/ast-summarizer (>=0.1.0, <=0.1.1), @agent-tool-platform/runtime (>=0.1.0, <=0.1.2) +582 more potentially affected by CVE-2026-84504 via fastify (>=5.0.0, <=5.12.1)

fastify NPM version =5.0.0, =0.1.0, =0.1.0, =0.1.0, =1.0.4, =0.0.0-vBETA-20260417080530, =0.0.1, =1.60.2, =1.0.0, =0.0.0, =2.0.1, =0.1.0, =0.1.0, =0.2.2 and more Source cves: CVE-2026-84504 Source advisory: SNYK:JS-FASTIFY-19639040...

CVE-2026-84504 fastify vulnerable to request body replacement via an async validation result collision

fastify versions before 5.12.2 treat the object resolved by a successful Ajv async validator as the value result protocol used by custom validator compilers. If a request that passes its route schema contains a property named value at the root, fastify replaces the entire request body with that...

EUVD-2026-70984

fastify versions before 5.12.2 treat the object resolved by a successful Ajv async validator as the value result protocol used by custom validator compilers. If a request that passes its route schema contains a property named value at the root, fastify replaces the entire request body with that...

CVE-2026-85184 @fastify/middie vulnerable to path-scoped middleware bypass via absolute-form request target

@fastify/middie versions = 9.1.0 and before 9.3.4 decide whether to run path-scoped middleware by matching against the raw request target, while the Fastify router resolves an absolute-form request target to its path before dispatching. Because the two layers evaluate different strings, a request...

CVE-2026-85184 @fastify/middie vulnerable to path-scoped middleware bypass via absolute-form request target

@fastify/middie versions = 9.1.0 and before 9.3.4 decide whether to run path-scoped middleware by matching against the raw request target, while the Fastify router resolves an absolute-form request target to its path before dispatching. Because the two layers evaluate different strings, a request...

CVE-2026-85184

@fastify/middie (a Fastify plugin for HTTP middleware) versions 9.1.0 through 9.3.3 are affected by a path-scoped middleware bypass. The root cause is a mismatch: middie evaluates the raw request target to decide whether to run path-scoped middleware, while the Fastify router resolves an absolute...

CVE-2026-85184 @fastify/middie vulnerable to path-scoped middleware bypass via absolute-form request target

@fastify/middie versions = 9.1.0 and before 9.3.4 decide whether to run path-scoped middleware by matching against the raw request target, while the Fastify router resolves an absolute-form request target to its path before dispatching. Because the two layers evaluate different strings, a request...

EUVD-2026-70979

@fastify/middie versions = 9.1.0 and before 9.3.4 decide whether to run path-scoped middleware by matching against the raw request target, while the Fastify router resolves an absolute-form request target to its path before dispatching. Because the two layers evaluate different strings, a request...

PT-2026-85451

fastify versions before 5.12.2 treat the object resolved by a successful Ajv async validator as the value result protocol used by custom validator compilers. If a request that passes its route schema contains a property named value at the root, fastify replaces the entire request body with that...

PT-2026-85472

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...

PT-2026-85467

fastify versions before 5.12.2 decide whether to compile a request schema based on JavaScript truthiness, but JSON Schema Draft 7 defines the boolean false as a valid schema that rejects every instance. When an application assigns false to a route's body, querystring, params, or headers schema to...