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

> An unauthenticated attacker can cause excessive resource consumption in kin-openapi by sending requests with many query keys, leading to denial of service.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Oct 2026
- **Updated:** 15 Oct 2026
- **Also known as:** GHSA-h4r5-mxv5-8mjc, UBUNTU-CVE-2026-100350

## What is CVE-2026-100350?

CVE-2026-100350 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. 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.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling), CWE-400 (Uncontrolled Resource Consumption), CWE-1050 (Excessive Platform Resource Consumption within a Loop)

## Which versions are affected by CVE-2026-100350?

2 open source packages ship an affected version, including github.com/getkin/kin-openapi.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/getkin/kin-openapi` | Go | From 0.145.0 | 0.146.0 |
| `github.com/getkin/kin-openapi` | Go | From 0.145.0 | 0.146.0 |

## How do I fix CVE-2026-100350?

Upgrade github.com/getkin/kin-openapi to 0.146.0 or later.

## Is CVE-2026-100350 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-100350 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-100350 and fix it if it is affected.

What it is: CVE-2026-100350 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.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-100350 exists.

Affected packages and fixed versions:
- github.com/getkin/kin-openapi (Go): affected from 0.145.0; fixed in 0.146.0
- github.com/getkin/kin-openapi (Go): affected from 0.145.0; fixed in 0.146.0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-100350/ (Markdown: https://insights.sbomify.com/CVE-2026-100350/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-100350
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-100350
- OSV: https://osv.dev/vulnerability/CVE-2026-100350

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-100350/
Summaries are generated and may contain mistakes; the official description above is the record.