# yawkat LZ4 Java: Native library extraction to a shared temporary directory is vulnerable to file replacement by another local user

Advisory record · `GHSA-mcr4-qmvw-px4g`

- **Identifiers:** `GHSA-mcr4-qmvw-px4g` · `CVE-2026-106451`
- **State:** Confirmed
- **Severity:** CVSS 7.3 High
- **Critical:** No
- **Weakness (CWE):** [CWE-367](https://cwe.mitre.org/data/definitions/367.html) · [CWE-377](https://cwe.mitre.org/data/definitions/377.html)
- **Tags:** [Race condition](https://agentprime.io/advisories/tag/race-condition.md) · [CWE-377](https://agentprime.io/advisories/tag/cwe-377.md)
- **Published:** 7 Oct 2026
- **Updated:** 7 Oct 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 7 Oct 2026, 20:35 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `at.yawk.lz4:lz4-java` (Maven): affected `<1.11.4`; fixed in `1.11.4`
- `org.lz4:lz4-java` (Maven): affected `>=1.7.0, <=1.8.1`; 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

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

- **CISA KEV:** Not listed.
- **EPSS:** 0.0011, the 1st percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 14:16 UTC: First seen by agentprime
- 31 Oct 2026, 14:16 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-mcr4-qmvw-px4g)

## Sources

- [GitHub Advisory Database: GHSA-mcr4-qmvw-px4g](https://github.com/advisories/GHSA-mcr4-qmvw-px4g)
- [OSV: GHSA-mcr4-qmvw-px4g](https://osv.dev/vulnerability/GHSA-mcr4-qmvw-px4g)
- <https://github.com/yawkat/lz4-java/security/advisories/GHSA-mcr4-qmvw-px4g>
- <https://nvd.nist.gov/vuln/detail/CVE-2026-106451>
- <https://github.com/yawkat/lz4-java/commit/7a48b7f6b8099b9dab6541e4ac2ee0979dc55aa3>
- <https://github.com/yawkat/lz4-java>
- <https://github.com/yawkat/lz4-java/releases/tag/v1.11.4>

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-mcr4-qmvw-px4g>, 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-mcr4-qmvw-px4g/>. Everything for agents: <https://agentprime.io/llms.txt>.