CVE-2026-97394
kin-openapi is a Go project for handling OpenAPI files.
Published Oct 15, 2026 · corrected/updated Oct 15, 2026 · evidence confidence high
### Summary A nil-pointer dereference in lets any unauthenticated client crash a request handler with a single HTTP request against an OpenAPI **3.1** operation that declares **without** . OpenAPI 3.1 (JSON Schema 2020-12) permits omitting , and accepts such schemas with . Request/response decoders then dereference with no nil check. The panic is **deterministic (100%)** on every request to the affected operation. There is no in ; under handlers without per-request recover the process can exit. ### Details **Spec-validation asymmetry.** OpenAPI 3.0 rejects array schemas that omit ([ ](https://github.com/getkin/kin-openapi/blob/master/openapi3/schema.go) around the / branch). For OpenAPI 3.1, enables , so that check is skipped and remains nil after a clean . **Vulnerable decoder.** The primary request-side crash is in [ ](https://github.com/getkin/kin-openapi/blob/master/openapi3filter/req_resp_decoder.go) (still present on this checkout at L1421): This runs during schema inspection **before** form values are parsed. Any non-empty body for the operation reaches the dereference (an empty body is rejected earlier when is true, and never enters the decoder). The same nil also crashes: | Path | Location | Trigger | |---|---|---| | | ~1564 → 1579 | part named like the array property | | → | ~1129 / 1151 | Array-typed **response headers** via , and path/cookie array params | / call / directly with no recover, so the panic escapes the library into the application. **Recommended fix.** Guard nil and return a structured decode/validation error, e.g.: Apply equivalent guards in and before calling . ### PoC Verified against revision , Go 1.25, . **1. Spec** — OpenAPI 3.1 operation with urlencoded body and property without : **2. E2E program** — server using the same public entrypoint ( → ) real middleware uses. Save as in a module that depends on at a vulnerable revision, then : **3. Observed output** ( ): Then: Server log: Stack pins the fault to at , called from → → . **Attac
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-2026-97394 is a high 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 (0.136.0 → 0.143.0); 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 7.5. It is not currently listed in the CISA Known Exploited catalog. Weakness classes: CWE-248, CWE-476. Sources contributing to this record: cve_org, github, gitlab, nvd. 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 the CISA KEV catalog.
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 0.136.0 until 0.143.0, openapi3filter accepts OpenAPI 3.1 array schemas without an items keyword and then dereferences the nil Schema.Items value while decoding application/x-www-form-urlencoded or multipart/form-data request bodies, response headers, and other array parameter surfaces. A remote unauthenticated client can reach an affect
Oct 15, 2026 · NIST NVD
Updated
kin-openapi is a Go project for handling OpenAPI files. From 0.136.0 until 0.143.0, openapi3filter accepts OpenAPI 3.1 array schemas without an items keyword and then dereferences the nil Schema.Items value while decoding application/x-www-form-urlencoded or multipart/form-data request bodies, response headers, and other array parameter surfaces. A remote unauthenticated client can reach an affect
Oct 15, 2026 · GitHub Advisory Database
Fix available
github.com/getkin/kin-openapi fixed in 0.143.0
Oct 15, 2026 · GitHub Advisory Database
Fix available
github.com/getkin/kin-openapi fixed in 0.143.0
Oct 15, 2026 · GitHub Advisory Database
Updated
### Summary A nil-pointer dereference in lets any unauthenticated client crash a request handler with a single HTTP request against an OpenAPI **3.1** operation that declares **without** . OpenAPI 3.1 (JSON Schema 2020-12) permits omitting , and accepts such schemas with . Request/response decoders then dereference with no nil check. The panic is **deterministic (100%)** on every request to the af
Affected
- Go github.com/getkin/kin-openapi0.136.0 → 0.143.0
- golang github.comversion unspecified
Sources
- CVE.orgVulnerability recordCVE-2026-97394
Official CVE identifier
cve.org - GitHub Advisory DatabasePackage advisoryGHSA-p6wj-qrr4-pgh5
GitHub Advisory Database record mirrored by OSV.
github.com - GitLab Advisory DatabasePackage advisoryCVE-2026-97394
A nil-pointer dereference in openapi3filter lets any unauthenticated client crash a request handler with a single HTTP request against an OpenAPI 3.1 operation that declares type: array without items. OpenAPI 3.1 (JSON Schema 2020-12) permits omitting items, and doc.Validate() accepts such schemas with Schema.Items == nil. Request/response decoders then dereference Items with no nil check. The pan
advisories.gitlab.com - NIST NVDVulnerability recordCVE-2026-97394
kin-openapi is a Go project for handling OpenAPI files. From 0.136.0 until 0.143.0, openapi3filter accepts OpenAPI 3.1 array schemas without an items keyword and then dereferences the nil Schema.Items value while decoding application/x-www-form-urlencoded or multipart/form-data r
nvd.nist.gov - OSV.devPackage advisoryGHSA-p6wj-qrr4-pgh5
kin-openapi: Nil-pointer dereference panic in openapi3filter for OpenAPI 3.1 array schemas missing items
osv.dev