How severe is CVE-2026-34726?

CVE-2026-34726 has a CVSS 3.x base score of 4.4, rated medium severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2026-34726 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (30th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-34726?

CVE-2026-34726 affects Copier-org Copier. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-34726?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-34726 have an EU (EUVD) identifier?

Yes. CVE-2026-34726 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-18495.

When was CVE-2026-34726 published?

CVE-2026-34726 was published on 2026-04-02 and last updated on 2026-06-17.

CVE-2026-34726

CVE-2026-34726 is a medium-severity vulnerability in Copier-org Copier with a CVSS 3.x base score of 4.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-22.

Key facts

Severity: Medium (CVSS 3.x base score 4.4)
EPSS exploit prediction: 0% (30th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-18495
Weakness: CWE-22
Affected product: Copier-org Copier
Published: 2026-04-02
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2026-34726?: 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.
How severe is CVE-2026-34726?: CVE-2026-34726 has a CVSS 3.x base score of 4.4, rated medium severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2026-34726 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (30th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-34726?: CVE-2026-34726 affects Copier-org Copier. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-34726?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-34726 have an EU (EUVD) identifier?: Yes. CVE-2026-34726 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-18495.
When was CVE-2026-34726 published?: CVE-2026-34726 was published on 2026-04-02 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:copier-org:copier:*:*:*:*:*:python:*:*

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