# \`nix-nar\`: \`Decoder::unpack\` writes archive entries outside the destination directory (path traversal) Advisory record · `RUSTSEC-2026-0425` - **Identifiers:** `RUSTSEC-2026-0425` - **State:** Confirmed - **Severity:** CVSS 7.5 High - **Critical:** No - **Published:** 30 Oct 2026 - **Updated:** 30 Oct 2026 - **Reviewed by a person:** No Published by OSV at 30 Oct 2026, 12:00 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. ## Affected packages - `nix-nar` (crates.io): affected `>=0.0.0-0, <0.6.0`; fixed in `0.6.0` ## Machine-written summary Summary written by Claude Haiku from the source advisory. Not reviewed by a person. > Versions of the nix-nar crate before 0.6.0 are affected. When a malicious NAR archive is unpacked with Decoder::unpack, its entries can be written outside the destination directory, through a symlink created earlier in the same archive followed by an entry that passes through it. An attacker who can supply the archive can create new files wherever the unpacking process has write access, and the source says this could be escalated to code execution. Upgrade to nix-nar 0.6.0 or later. The source lists no other workaround. Written 3 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 - 7.5 High, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N`, from OSV - **CISA KEV:** Not listed. - **EPSS:** No score. ## Timeline - 31 Oct 2026, 14:24 UTC: First seen by agentprime - 31 Oct 2026, 14:24 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/RUSTSEC-2026-0425) ## Sources - [OSV: RUSTSEC-2026-0425](https://osv.dev/vulnerability/RUSTSEC-2026-0425) - - - 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: .