What’s Vulnerable › Vulnerabilities

CVE-2026-76905: kin-openapi openai3filter: nil-pointer panic in ConvertErrors on malformed multipart/form-data body enables unauthenticated DoS

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-21 · updated 2026-10-12
• Weakness: CWE-476

Description

kin-openapi is a Go project for handling OpenAPI files. From 0.10.0 until 0.141.0, openapi3filter.convertParseError in openapi3filter/validation_error_encoder.go dereferences e.Parameter.In without checking whether e.Parameter is nil. A malformed non-string scalar field in a multipart/form-data request body produces a nested ParseError with a nil RequestError.Parameter, and applications that render the validation error through openapi3filter.ConvertErrors or ValidationErrorEncoder panic. An unauthenticated client can repeatedly send such requests to deny service when the application lacks a recovery boundary. JSON request bodies and applications that do not use these error-rendering helpers are not affected. This issue is fixed in version 0.141.0.

Affected products

• getkin kin-openapi: from 0.10.0, < 0.141.0

References

• https://github.com/getkin/kin-openapi/commit/1d0a337c9b1570fab283be8a04c8af6e43b9a22c
• https://github.com/getkin/kin-openapi/releases/tag/v0.141.0
• https://github.com/getkin/kin-openapi/security/advisories/GHSA-mmfr-pmjx-hw9w
• https://github.com/getkin/kin-openapi/security/advisories/GHSA-mmfr-pmjx-hw9w

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