How severe is CVE-2026-34730?

CVE-2026-34730 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2026-34730 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (21st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-34730?

CVE-2026-34730 affects Copier-org Copier. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-34730?

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

Does CVE-2026-34730 have an EU (EUVD) identifier?

Yes. CVE-2026-34730 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-18497.

When was CVE-2026-34730 published?

CVE-2026-34730 was published on 2026-04-02 and last updated on 2026-06-17.

CVE-2026-34730

CVE-2026-34730 is a medium-severity vulnerability in Copier-org Copier with a CVSS 3.x base score of 5.5. 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 5.5)
EPSS exploit prediction: 0% (21st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-18497
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 _external_data feature allows a template to load YAML files using template-controlled paths. If untrusted templates are in scope, a malicious template can read attacker-chosen YAML-parseable local files that are accessible to the user running Copier and expose their contents in rendered output. This issue has been patched in version 9.14.1.

Frequently asked questions

What is CVE-2026-34730?: Copier is a library and CLI app for rendering project templates. Prior to version 9.14.1, Copier's _external_data feature allows a template to load YAML files using template-controlled paths. If untrusted templates are in scope, a malicious template can read attacker-chosen YAML-parseable local files that are accessible to the user running Copier and expose their contents in rendered output. This issue has been patched in version 9.14.1.
How severe is CVE-2026-34730?: CVE-2026-34730 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2026-34730 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (21st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-34730?: CVE-2026-34730 affects Copier-org Copier. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-34730?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-34730 have an EU (EUVD) identifier?: Yes. CVE-2026-34730 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-18497.
When was CVE-2026-34730 published?: CVE-2026-34730 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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