---
id: CVE-2026-73248
title: calibre is an e-book manager
summary: >-
  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 inhe…
severity: none
cwe:
  - CWE-94
  - CWE-95
published: '2026-08-11'
updated: '2026-09-09'
sourceUpdated: '2026-09-09T20:55:04.493'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-73248'
references:
  - url: >-
      https://github.com/kovidgoyal/calibre/commit/dac9990458374a81a5372a768bba6527d965aac8
    label: security-advisories@github.com
  - url: 'https://github.com/kovidgoyal/calibre/releases/tag/v9.12.0'
    label: security-advisories@github.com
  - url: >-
      https://github.com/kovidgoyal/calibre/security/advisories/GHSA-4f7g-rjfp-hmvx
    label: security-advisories@github.com
  - url: >-
      https://github.com/kovidgoyal/calibre/security/advisories/GHSA-4f7g-rjfp-hmvx
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
epss: 0.00197
epssPercentile: 0.08387
ingestedAt: '2026-09-09T21:22:45.530Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.