What’s Vulnerable › Vulnerabilities

CVE-2026-100350: kin-openapi deepObject query decoding repeatedly compiles an invariant regular expression

• Severity: medium (CVSS 5.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-15 · updated 2026-10-15
• Weakness: CWE-400

Description

kin-openapi is a Go project for handling OpenAPI files. From 0.145.0 until 0.146.0, openapi3filter repeatedly calls regexp.MustCompile for the same parameter-name regular expression inside the per-query-key loop in urlValuesDecoder.DecodeObject used to decode a deepObject query parameter. An unauthenticated remote client can send an affected endpoint a request containing many unrelated query keys, causing ValidateRequest to perform work and allocations proportional to the attacker-controlled key count for every deepObject parameter. The expression itself is fixed and this is not regular expression denial of service; the resource consumption comes from loop-invariant recompilation. This issue is fixed in version 0.146.0.

Affected products

• getkin kin-openapi: from 0.145.0, < 0.146.0

References

• https://github.com/getkin/kin-openapi/commit/d090e36b2f1c42c898ba2a687a8f6e25f5ca727f
• https://github.com/getkin/kin-openapi/releases/tag/v0.146.0
• https://github.com/getkin/kin-openapi/security/advisories/GHSA-h4r5-mxv5-8mjc
• https://github.com/getkin/kin-openapi/security/advisories/GHSA-h4r5-mxv5-8mjc

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