calibre is an e-book manager. Prior to 9.12.0, calibre processes attacker-controlled compositetemplate metadata from a malicious EPUB, OPF, PDF, or similar file through program: and a nested template() call whose formatter does not inherit allowpythontemplates=False, allowing a nested python: template to reach compilepython_template and execute arbitrary Python code when the file is opened or imported. This issue is fixed in version 9.12.0.
{
"cwe_ids": [
"CWE-94",
"CWE-95"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/73xxx/CVE-2026-73248.json",
"cna_assigner": "GitHub_M"
}