Vulnerability · CVE-2026-100350
kin-openapi is a Go project for handling OpenAPI files.
Published Oct 15, 2026 · corrected/updated Oct 15, 2026 · evidence confidence high
### Summary decodes -style query parameters by looping over **every** key in the request's query string. Inside that loop it recompiles a **loop-invariant** regular expression on every iteration. The pattern depends only on the spec-defined parameter name, not on the loop variable, so it is compiled times for query keys instead of once. Because the number of query keys is attacker-controlled and unbounded, a single request with many junk query keys forces a proportional number of calls, consuming CPU. A handful of concurrent requests can saturate all cores — an uncontrolled-resource-consumption denial of service. This is **not** ReDoS: the pattern is fixed ( ) and matches in linear time. The cost is the **repeated compilation** of an invariant regexp, once per attacker-supplied query key. ### Details In , the branch of builds a per-parameter property map by iterating over all query keys: The regexp built at depends only on — the parameter name defined in the OpenAPI spec — which is **constant** for the whole loop. Yet is invoked inside the loop at , so it is recompiled once for every key present in the query string. Contrast this with the already-hoisted, package-level regexp used two lines below: is compiled exactly once at package init and reused. The per-parameter pattern at should be compiled the same way (once, outside the loop), but instead is rebuilt on every iteration. costs on the order of a few microseconds per call. The number of iterations equals the number of query keys , which the client fully controls (a ~1 MB URL holds roughly 100k keys). For each parameter defined on the matched route, the request performs compilations. The work is CPU-bound, happens during request validation before any handler logic, and scales linearly with request size, so an attacker converts cheap request bytes into expensive server CPU. Affected code path: → → → (the case). Any operation with at least one , parameter is exploitable. ### PoC The following self-contained test (p
Grounded briefings
Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.
Executive
CVE-2026-100350 is a medium public vulnerability record for this product. It is not currently listed in the CISA Known Exploited catalog. Check the linked vendor or CERT advisories for patch status. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.
System administrator
Identify whether this product is in your estate, then compare installed versions with the affected ranges. Affected packages or ranges on record: github.com/getkin/kin-openapi (0.145.0 → 0.146.0); github.com/getkin/kin-openapi (>= 0.145.0, < 0.146.0); github.com. Check the linked vendor or CERT advisories for patch status. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.
Security analyst
Signals on file: CVSS 5.3, EPSS 0.5%. It is not currently listed in the CISA Known Exploited catalog. Weakness classes: CWE-1050, CWE-400, CWE-770. Sources contributing to this record: cve_org, epss, github, gitlab. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.
Exploitation and remediation
Exploitation evidence
Not listed as known exploited in CISA KEV. Not in CISA KEV or VulnCheck KEV.
Patch and remediation
No required-action text is stored yet. Use the vendor or CERT links in Sources for patch availability.
Safe detection guidance
Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
Oct 15, 2026 · NIST NVD
Detected
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,
Oct 15, 2026 · NIST NVD
Updated
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,
Oct 15, 2026 · NIST NVD
Updated
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,
Oct 15, 2026 · GitHub Advisory Database
Fix available
github.com/getkin/kin-openapi fixed in 0.146.0
Oct 15, 2026 · GitHub Advisory Database
Fix available
github.com/getkin/kin-openapi fixed in 0.146.0
Oct 15, 2026 · GitHub Advisory Database
Updated
### Summary decodes -style query parameters by looping over **every** key in the request's query string. Inside that loop it recompiles a **loop-invariant** regular expression on every iteration. The pattern depends only on the spec-defined parameter name, not on the loop variable, so it is compiled times for query keys instead of once. Because the number of query keys is attacker-controlled and u
Affected
- Go github.com/getkin/kin-openapi0.145.0 → 0.146.0
- go github.com/getkin/kin-openapi>= 0.145.0, < 0.146.0
- golang github.comversion unspecified
Sources
- CVE.orgVulnerability recordCVE-2026-100350
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2026-100350
30-day exploitation probability 0.5%
first.org - GitHub Advisory DatabasePackage advisoryGHSA-h4r5-mxv5-8mjc
kin-openapi deepObject query decoding repeatedly compiles an invariant regular expression
github.com - GitLab Advisory DatabasePackage advisoryCVE-2026-100350
openapi3filter decodes deepObject-style query parameters by looping over every key in the request's query string. Inside that loop it recompiles a loop-invariant regular expression on every iteration. The pattern depends only on the spec-defined parameter name, not on the loop variable, so it is compiled N times for N query keys instead of once. Because the number of query keys is attacker-control
advisories.gitlab.com - NIST NVDVulnerability recordCVE-2026-100350
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 p
nvd.nist.gov - OpenSSF OSV / OSV ScannerPackage advisoryGHSA-h4r5-mxv5-8mjc
kin-openapi deepObject query decoding repeatedly compiles an invariant regular expression
osv.dev