calibre is an e-book manager. Prior to 9.12.0, calibre processes attacker-controlled composite_template metadata from a malicious EPUB, OPF, PDF, or similar file through program: and a nested template() call whose formatter does not inherit allow_python_templates=False, allowing a nested python: template to reach compile_python_template and execute arbitrary Python code when the file is opened or imported. This issue is fixed in version 9.12.0.

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History

Tue, 11 Aug 2026 22:15:00 +0000

Type Values Removed Values Added
Description calibre is an e-book manager. Prior to 9.12.0, calibre processes attacker-controlled composite_template metadata from a malicious EPUB, OPF, PDF, or similar file through program: and a nested template() call whose formatter does not inherit allow_python_templates=False, allowing a nested python: template to reach compile_python_template and execute arbitrary Python code when the file is opened or imported. This issue is fixed in version 9.12.0.
Title calibre: Bypass of Python template restrictions via nested `template()` leading to RCE
Weaknesses CWE-94
CWE-95
References
Metrics cvssV4_0

{'score': 8.5, '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'}


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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-08-11T21:56:08.569Z

Reserved: 2026-08-11T17:18:01.597Z

Link: CVE-2026-73248

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-11T22:19:05.553

Modified: 2026-08-11T22:19:05.553

Link: CVE-2026-73248

cve-icon Redhat

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cve-icon OpenCVE Enrichment

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Weaknesses