CVE-2026-34726

low-risk
Published 2026-04-02

Copier is a library and CLI app for rendering project templates. Prior to version 9.14.1, Copier's _subdirectory setting is documented as the subdirectory to use as the template root. However, the current implementation accepts parent-directory traversal such as .. and uses it directly when selecting the template root. As a result, a template can escape its own directory and make Copier render files from the parent directory without --UNSAFE. This issue has been patched in version 9.14.1.

Do I need to act?

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0.02% chance of exploitation
EPSS score — low exploit probability
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Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
4
CVSS 4.4/10 Medium
LOCAL / LOW complexity

Affected Products (1)

Copier

Affected Vendors

20
/ 100
low-risk
Severity 15/34 · Moderate
Exploitability 0/34 · Minimal
Exposure 5/34 · Minimal