Description
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.
Published: 2026-08-21
Score: 8.7 High
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

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Tracking

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-xhj3-7xw9-vr34 kin-openapi has uncontrolled resource consumption in openapi3filter deepObject query parameter decoding
History

Fri, 21 Aug 2026 21:00:00 +0000

Type Values Removed Values Added
Description 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.
Title kin-openapi: Uncontrolled resource consumption in openapi3filter deepObject query parameter decoding
Weaknesses CWE-400
CWE-789
References
Metrics cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}

Subscriptions

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-08-21T20:44:47.792Z

Reserved: 2026-08-20T19:28:35.244Z

Link: CVE-2026-77354

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-21T21:17:07.130

Modified: 2026-08-21T21:17:07.130

Link: CVE-2026-77354

cve-icon Redhat

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cve-icon OpenCVE Enrichment

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Weaknesses
  • CWE-400

    Uncontrolled Resource Consumption

  • CWE-789

    Memory Allocation with Excessive Size Value