# Local Information Disclosure Vulnerability in Netty on Unix-Like systems Advisory record · `GHSA-5mcr-gq6c-3hq2` - **Identifiers:** `GHSA-5mcr-gq6c-3hq2` · `CVE-2021-21290` - **State:** Confirmed - **Severity:** CVSS 6.2 Medium - **Critical:** No - **Weakness (CWE):** [CWE-378](https://cwe.mitre.org/data/definitions/378.html) · [CWE-379](https://cwe.mitre.org/data/definitions/379.html) · [CWE-668](https://cwe.mitre.org/data/definitions/668.html) - **Tags:** [Information disclosure](https://agentprime.io/advisories/tag/info-disclosure.md) · [CWE-378](https://agentprime.io/advisories/tag/cwe-378.md) · [CWE-379](https://agentprime.io/advisories/tag/cwe-379.md) - **Published:** 8 Feb 2021 - **Updated:** 10 Sept 2026 - **Reviewed by a person:** No Published by the GitHub Advisory Database at 8 Feb 2021, 21:17 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. ## Affected packages - `io.netty:netty-codec-http` (Maven): affected `>=4.0.0, <4.1.59.Final`; fixed in `4.1.59.Final` - `org.jboss.netty:netty` (Maven): affected `all versions`; no fixed version yet - `io.netty:netty` (Maven): affected `all versions`; no fixed version yet ## Machine-written summary Summary written by Claude Haiku from the source advisory. Not reviewed by a person. > Netty's io.netty:netty-codec-http package, versions 4.0.0 up to but not including 4.1.59.Final, can leak information through the system temporary directory when multipart uploads are stored on disk. A local user on a shared Unix-like system could read the temporary files, which may contain sensitive uploaded data. Upgrade to 4.1.59.Final or later. Alternatively, set a private java.io.tmpdir or call DefaultHttpDataFactory.setBaseDir to a directory readable only by the current user. No fixed version is listed for org.jboss.netty:netty or io.netty:netty. Written 2 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 - 6.2 Medium, CVSS 3.1: `CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`, from CNA (GitHub_M) - **CISA KEV:** Not listed. - **EPSS:** 0.018, the 78th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days. ## Timeline - 31 Oct 2026, 14:18 UTC: First seen by agentprime - 31 Oct 2026, 14:18 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-5mcr-gq6c-3hq2) ## Sources - [GitHub Advisory Database: GHSA-5mcr-gq6c-3hq2](https://github.com/advisories/GHSA-5mcr-gq6c-3hq2) - [OSV: GHSA-5mcr-gq6c-3hq2](https://osv.dev/vulnerability/GHSA-5mcr-gq6c-3hq2) - - - - - - - - - - - - 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 (), 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: - In a browser: reads your lockfile in the browser, never uploading it. - Whether it touches your code, with file and line: the Claude Code plugin, - As JSON: , or `POST https://api.agentprime.io/v1/match` with your packages () --- The web page: . Everything for agents: .