kin-openapi: Uncontrolled Recursion on Circular allOf/anyOf/oneOf Schemas Causes Fatal Process Crash

[ 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 0.149.0, runtime request, response, and direct schema validation lacks cycle detection when an allOf, anyOf, or oneOf chain refers back to an ancestor schema, even though loading and document validation accept the circular reference. A request or response that reaches the affected schema causes unbounded recursion in Schema.visitJSON or openapi3filter.decodeValue and exhausts the Go goroutine stack. The resulting fatal stack overflow cannot be caught with recover and terminates the entire process, including unrelated requests. This issue is fixed in version 0.149.0.

[ Fixes ]Fixes and patches

• github.com/getkin/kin-openapi 0.149.0Fixed version · GitHub Advisories · go package github.com/getkin/kin-openapi: upgrade to 0.149.0 or later (affected < 0.149.0)

[ Packages ]Affected open-source packages

• github.com/getkin/kin-openapi goAffected < 0.149.0 · fixed in 0.149.0 · GHSA-g8cf-rcjf-c8cf

[ References ]References

• github.com/getkin/kin-openapi/commit/9245cef66c840e27a08409a8a5cd0ee930c5bcff
• github.com/getkin/kin-openapi/releases/tag/v0.149.0
• github.com/getkin/kin-openapi/security/advisories/GHSA-g8cf-rcjf-c8cf