# Copier safe template has arbitrary filesystem write access via directory symlinks when \_preserve_symlinks: true

Advisory record · `GHSA-4fqp-r85r-hxqh`

- **Identifiers:** `GHSA-4fqp-r85r-hxqh` · `CVE-2026-23986` · `PYSEC-2026-1272`
- **State:** Confirmed
- **Severity:** CVSS 6.9 Medium
- **Critical:** No
- **Weakness (CWE):** [CWE-61](https://cwe.mitre.org/data/definitions/61.html)
- **Tags:** [CWE-61](https://agentprime.io/advisories/tag/cwe-61.md)
- **Published:** 21 Jan 2026
- **Updated:** 7 Jul 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 21 Jan 2026, 22:19 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `copier` (PyPI): affected `<9.11.2`; fixed in `9.11.2`

## 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

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

- **CISA KEV:** Not listed.
- **EPSS:** 0.0027, the 19th percentile, on 7 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

This record came from the full history of the GitHub Advisory Database, published 21 Jan 2026. New records show when each source confirmed them.

## Sources

- [GitHub Advisory Database: GHSA-4fqp-r85r-hxqh](https://github.com/advisories/GHSA-4fqp-r85r-hxqh)
- [OSV: GHSA-4fqp-r85r-hxqh](https://osv.dev/vulnerability/GHSA-4fqp-r85r-hxqh)
- <https://github.com/copier-org/copier/security/advisories/GHSA-4fqp-r85r-hxqh>
- <https://nvd.nist.gov/vuln/detail/CVE-2026-23986>
- <https://github.com/copier-org/copier/commit/b3a7b3772d17cf0e7a4481978188c9f536c8d8f6>
- <https://github.com/copier-org/copier>
- <https://github.com/copier-org/copier/releases/tag/v9.11.2>

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-4fqp-r85r-hxqh>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

---

The web page: <https://agentprime.io/advisories/GHSA-4fqp-r85r-hxqh/>. Everything for agents: <https://agentprime.io/llms.txt>.