# HTTP Request Smuggling in Netty

Advisory record · `GHSA-cqqj-4p63-rrmm`

- **Identifiers:** `GHSA-cqqj-4p63-rrmm` · `CVE-2019-20444`
- **State:** Confirmed
- **Severity:** CVSS 9.1 Critical
- **Critical:** Yes: CVSS 9+
- **Weakness (CWE):** [CWE-444](https://cwe.mitre.org/data/definitions/444.html)
- **Tags:** [HTTP request smuggling](https://agentprime.io/advisories/tag/request-smuggling.md)
- **Published:** 21 Feb 2020
- **Updated:** 2 Jul 2025
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 21 Feb 2020, 18:55 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Critical

Critical, because:

- CVSS score 9.1: 9.0 or more.

How we decide what’s critical: <https://agentprime.io/advisories/critical.md>

## Affected packages

- `io.netty:netty-codec-http` (Maven): affected `<4.1.44`; fixed in `4.1.44`
- `org.jboss.netty:netty` (Maven): affected `all versions`; no fixed version yet
- `io.netty:netty` (Maven): affected `all versions`; no fixed version yet

## 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

- 9.1 Critical, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N`, from GitHub Advisory Database

- **CISA KEV:** Not listed.
- **EPSS:** 0.089, the 95th percentile, on 8 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 15:10 UTC: First seen by agentprime
- 31 Oct 2026, 15:10 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-cqqj-4p63-rrmm)

## Sources

- [GitHub Advisory Database: GHSA-cqqj-4p63-rrmm](https://github.com/advisories/GHSA-cqqj-4p63-rrmm)
- [OSV: GHSA-cqqj-4p63-rrmm](https://osv.dev/vulnerability/GHSA-cqqj-4p63-rrmm)
- <https://nvd.nist.gov/vuln/detail/CVE-2019-20444>
- <https://github.com/netty/netty/issues/9866>
- <https://github.com/netty/netty/pull/9871/files#diff-e26989b9171ef22c27c9f7d80689cfb059d568c9bd10e75970d96c02d0654878>
- <https://github.com/netty/netty/pull/9871>
- <https://lists.apache.org/thread.html/ra9fbfe7d4830ae675bf34c7c0f8c22fc8a4099f65706c1bc4f54c593%40%3Cissues.zookeeper.apache.org%3E>
- <https://lists.apache.org/thread.html/ra9fbfe7d4830ae675bf34c7c0f8c22fc8a4099f65706c1bc4f54c593@%3Cissues.zookeeper.apache.org%3E>
- <https://lists.apache.org/thread.html/raaac04b7567c554786132144bea3dcb72568edd410c1e6f0101742e7%40%3Cissues.flink.apache.org%3E>
- <https://lists.apache.org/thread.html/raaac04b7567c554786132144bea3dcb72568edd410c1e6f0101742e7@%3Cissues.flink.apache.org%3E>
- <https://lists.apache.org/thread.html/rb3361f6c6a5f834ad3db5e998c352760d393c0891b8d3bea90baa836%40%3Ccommon-issues.hadoop.apache.org%3E>
- <https://lists.apache.org/thread.html/rb3361f6c6a5f834ad3db5e998c352760d393c0891b8d3bea90baa836@%3Ccommon-issues.hadoop.apache.org%3E>
- <https://lists.apache.org/thread.html/rb84c57670ec48ef23f4d07973b7fa69f629b8e7fcfb48874362feb6f%40%3Ccommits.zookeeper.apache.org%3E>
- <https://lists.apache.org/thread.html/rb84c57670ec48ef23f4d07973b7fa69f629b8e7fcfb48874362feb6f@%3Ccommits.zookeeper.apache.org%3E>

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-cqqj-4p63-rrmm>, 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-cqqj-4p63-rrmm/>. Everything for agents: <https://agentprime.io/llms.txt>.