CVE-2026-23968 Copier safe template has arbitrary filesystem read access via symlinks when _preserve_symlinks: false

Medium 6.8 Published 21 Jan 2026 Updated 22 Jan 2026

Attackers can read arbitrary files outside the template directory via symlinks in safe templates, affecting users of the Copier library.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Local or same network only
Victim action needed: A user has to click or open something
Fix: Available

What is CVE-2026-23968?

CVE-2026-23968 is a medium-severity path traversal vulnerability in copier-org copier, published on 21 Jan 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

Official description

Copier is a library and CLI app for rendering project templates. Prior to version 9.11.2, Copier suggests that it's safe to generate a project from a safe template, i.e. one that doesn't use unsafe features like custom Jinja extensions which would require passing the `--UNSAFE,--trust` flag. As it turns out, a safe template can currently include arbitrary files/directories outside the local template clone location by using symlinks along with `_preserve_symlinks: false` (which is Copier's default setting). Version 9.11.2 patches the issue.

Weakness: CWE-61

Which versions are affected by CVE-2026-23968?

3 open source packages ship an affected version, including copier. It affects 1 product.

Package	Affected	Fixed in
`copier` PyPI	All versions	`9.11.2`
`copier` PyPI	All versions	`9.11.2`
`copier` PyPI	All versions	`9.11.2`

Products include Copier-Org Copier.

How do I fix CVE-2026-23968?

Upgrade copier to 9.11.2 or later.

Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.

Is CVE-2026-23968 being exploited?

There is no known exploitation of CVE-2026-23968 in the wild and no public exploit code.

Sources

Also known as GHSA-xjhm-gp88-8pfx, PYSEC-2026-1274.