CVE-2026-100347 kin-openapi: Unauthenticated panic (DoS) in openapi3filter legacy router via non-canonical/unsupported HTTP method on a static path
Unauthenticated attackers can cause a denial of service by sending non-canonical HTTP methods to static paths, triggering a panic in the kin-openapi library.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-100347?
CVE-2026-100347 is a medium-severity denial of service vulnerability in getkin kin-openapi, published on 15 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
kin-openapi is a Go project for handling OpenAPI files. Prior to 0.145.0, openapi3filter.ValidationHandler uses the routers/legacy router, which passes an unsupported or non-canonical HTTP method for an existing static path to openapi3.PathItem.GetOperation. The default branch of GetOperation panics before authentication runs, so an unauthenticated remote client can repeatedly send methods such as PROPFIND or lowercase get to abort connections and generate stack-trace log growth. The specific panic requires an exact static path; a concrete path matched only by a templated route does not reach the same sink. This issue is fixed in version 0.145.0.
Which versions are affected by CVE-2026-100347?
2 open source packages ship an affected version, including github.com/getkin/kin-openapi.
| Package | Affected | Fixed in |
|---|---|---|
github.com/getkin/kin-openapi Go | All versions | 0.145.0 |
github.com/getkin/kin-openapi Go | All versions | 0.145.0 |
How do I fix CVE-2026-100347?
Upgrade github.com/getkin/kin-openapi to 0.145.0 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-100347 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-100347 exists.
Sources
Also known as CLEANSTART-2026-RK72601, DEBIAN-CVE-2026-100347, ECHO-6d09-b18b-72ae, GHSA-fh4f-47mf-f2gj, MINI-2c38-px6r-749c, MINI-2qx7-3mvx-3329 and 31 more.