# kin-openapi has uncontrolled resource consumption in openapi3filter deepObject query parameter decoding

Advisory record · `GHSA-xhj3-7xw9-vr34`

- **Identifiers:** `GHSA-xhj3-7xw9-vr34` · `CVE-2026-77354` · `GO-2026-6275`
- **State:** Confirmed
- **Severity:** CVSS 8.7 High
- **Critical:** No
- **Weakness (CWE):** [CWE-400](https://cwe.mitre.org/data/definitions/400.html) · [CWE-789](https://cwe.mitre.org/data/definitions/789.html)
- **Tags:** [Denial of service](https://agentprime.io/advisories/tag/dos.md)
- **Published:** 21 Aug 2026
- **Updated:** 10 Sept 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 21 Aug 2026, 20:56 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `github.com/getkin/kin-openapi` (Go): affected `>=0.124.0, <0.142.0`; fixed in `0.142.0`

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> kin-openapi versions from 0.124.0 before 0.142.0 are affected. An unauthenticated remote client can send a small HTTP request with a crafted deepObject query parameter to an application that validates requests with openapi3filter, causing gigabytes of memory allocation and possible out-of-memory crashes. Upgrade to version 0.142.0. No fix is needed beyond that upgrade.

Written 1 Nov 2026.

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 8.7 High, CVSS 4.0: `CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`, from CNA (GitHub_M)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0052, the 45th percentile, on 14 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 14:13 UTC: First seen by agentprime
- 31 Oct 2026, 14:13 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-xhj3-7xw9-vr34)

## Sources

- [GitHub Advisory Database: GHSA-xhj3-7xw9-vr34](https://github.com/advisories/GHSA-xhj3-7xw9-vr34)
- [OSV: GHSA-xhj3-7xw9-vr34](https://osv.dev/vulnerability/GHSA-xhj3-7xw9-vr34)
- <https://github.com/getkin/kin-openapi/security/advisories/GHSA-xhj3-7xw9-vr34>
- <https://github.com/getkin/kin-openapi/commit/1223a0f215d2cf9beb2d9eb9ea2649d001c21388>
- <https://github.com/getkin/kin-openapi>
- <https://github.com/getkin/kin-openapi/releases/tag/v0.142.0>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-xhj3-7xw9-vr34>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-xhj3-7xw9-vr34/>. Everything for agents: <https://agentprime.io/llms.txt>.