# CVE-2026-73248: calibre: calibre is an e-book manager

CVE-2026-73248 is fixed in 3 products on 1 platform, first by DEBIAN-CVE-2026-73248, released August 13, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-73248
- Priority: Routine
- CVSS: n/a
- EPSS: 0.0020
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Aug 11, 2026

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | calibre Debian 14 | 9.12.0+ds+~0.10.6-1 | [DEBIAN-CVE-2026-73248](https://patchblox.com/security/data/fix/linux/debian-cve-2026-73248.md) | Aug 13, 2026 |
| Linux | calibre Fedora 43 | 9.13.0-1.fc43 | [FEDORA-2026-C10ED2F3B7](https://patchblox.com/security/data/fix/linux/fedora-2026-c10ed2f3b7.md) | Aug 16, 2026 |
| Linux | calibre-debuginfo Fedora 43 | 9.13.0-1.fc43 | [FEDORA-2026-C10ED2F3B7](https://patchblox.com/security/data/fix/linux/fedora-2026-c10ed2f3b7.md) | Aug 16, 2026 |
| Linux | calibre-debugsource Fedora 43 | 9.13.0-1.fc43 | [FEDORA-2026-C10ED2F3B7](https://patchblox.com/security/data/fix/linux/fedora-2026-c10ed2f3b7.md) | Aug 16, 2026 |

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Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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