kin-openapi: YAML NaN/Inf Values Bypass Built-in Guards and Panic via OAS 3.1 Validation Path

[ Why it matters ]Priority signals

• Public proof-of-concept exploit exists (CISA SSVC)

[ Description ]Official description

kin-openapi is a Go project for handling OpenAPI files. Prior to 0.148.0, the OpenAPI 3.1 validation path passes YAML NaN and infinity numeric values to santhosh-tekuri/jsonschema v6.0.2 without applying kin-openapi's existing finite-number guards. A remote unauthenticated client can send an application/yaml or application/x-yaml request body containing .nan, .inf, or -.inf to an operation with a numeric constraint, causing the dependency to create and dereference a nil big.Rat during ValidateRequest. Standard net/http servers recover the panic per connection, while other hosts or application goroutines may terminate the process. This issue is fixed in version 0.148.0.

[ Fixes ]Fixes and patches

• github.com/getkin/kin-openapi 0.148.0Fixed version · GitHub Advisories · go package github.com/getkin/kin-openapi: upgrade to 0.148.0 or later (affected < 0.148.0)

[ Packages ]Affected open-source packages

• github.com/getkin/kin-openapi goAffected < 0.148.0 · fixed in 0.148.0 · GHSA-rj39-cv6w-8wv7

[ References ]References

• github.com/getkin/kin-openapi/commit/4487f198ab8be0c37d6ca72c54f5dca4dc25270e
• github.com/getkin/kin-openapi/releases/tag/v0.148.0
• github.com/getkin/kin-openapi/security/advisories/GHSA-rj39-cv6w-8wv7