CVE-2026-77354

CVE-2026-77354 · kin-openapi: Uncontrolled resource consumption in openapi3filter deepObject query parameter decoding

This page contains facts from public vulnerability sources. Check the original advisory before updating.

kin-openapi is a Go project for handling OpenAPI files. From 0.124.0 until 0.142.0, openapi3filter.sliceMapToSlice in openapi3filter/req_resp_decoder.go converts attacker-controlled sparse indexes from a deepObject query parameter into a dense slice by allocating entries from zero through the largest supplied index, after which buildResObj creates another slice of the same length. This allocation occurs before schema validation, so maxItems does not prevent it. An unauthenticated client can send a small query such as param[items][50000000]=x to an endpoint whose deepObject schema contains an array, forcing multi-gigabyte heap allocation and causing an OOM kill or restart loop. Other request-body encodings and styled parameters that do not produce bracketed integer indexes are not affected. This issue is fixed in version 0.142.0.

CVSS 8.7 · High · EPSS 0.5%

Published

2026-08-21T20:44:47.792Z

Updated

2026-08-25T19:15:23.235Z

Stack: system

Check your server →