CVE-2026-53511: CWE-94: Improper Control of Generation of Code ('Code Injection') in kovidgoyal calibre
calibre is an e-book manager. Prior to 9.10.0, a malicious EPUB, OPF, or PDF file can execute arbitrary Python code when its metadata is read by calibre, including through Add books or Edit books, by embedding a custom column definition with a python: template in calibre:user_metadata that is passed unsanitized to exec() in the template formatter. This issue is fixed in version 9.10.0.
AI Analysis
Technical Summary
CVE-2026-53511 is a code injection vulnerability (CWE-94) in the calibre e-book manager. Before version 9.10.0, calibre improperly controls the generation of code by passing unsanitized python: templates embedded in custom column definitions within calibre:user_metadata to the exec() function in the template formatter. This allows a maliciously crafted EPUB, OPF, or PDF file to execute arbitrary Python code when its metadata is read, such as during Add books or Edit books operations. The vulnerability is fixed in calibre version 9.10.0.
Potential Impact
An attacker can execute arbitrary Python code on the system running calibre by supplying a specially crafted e-book file. This can lead to full compromise of the user's environment with the privileges of the calibre process. The vulnerability requires user interaction (opening or editing a malicious file) and local access to the vulnerable application.
Mitigation Recommendations
Upgrade calibre to version 9.10.0 or later, where this vulnerability is fixed. No other official remediation or temporary fix is indicated. Users should avoid opening untrusted EPUB, OPF, or PDF files in vulnerable versions until patched.
CVE-2026-53511: CWE-94: Improper Control of Generation of Code ('Code Injection') in kovidgoyal calibre
Description
calibre is an e-book manager. Prior to 9.10.0, a malicious EPUB, OPF, or PDF file can execute arbitrary Python code when its metadata is read by calibre, including through Add books or Edit books, by embedding a custom column definition with a python: template in calibre:user_metadata that is passed unsanitized to exec() in the template formatter. This issue is fixed in version 9.10.0.
CVSS v4.0
Score 8.5high
Affected software
pkg:github/kovidgoyal/calibreRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-53511 is a code injection vulnerability (CWE-94) in the calibre e-book manager. Before version 9.10.0, calibre improperly controls the generation of code by passing unsanitized python: templates embedded in custom column definitions within calibre:user_metadata to the exec() function in the template formatter. This allows a maliciously crafted EPUB, OPF, or PDF file to execute arbitrary Python code when its metadata is read, such as during Add books or Edit books operations. The vulnerability is fixed in calibre version 9.10.0.
Potential Impact
An attacker can execute arbitrary Python code on the system running calibre by supplying a specially crafted e-book file. This can lead to full compromise of the user's environment with the privileges of the calibre process. The vulnerability requires user interaction (opening or editing a malicious file) and local access to the vulnerable application.
Mitigation Recommendations
Upgrade calibre to version 9.10.0 or later, where this vulnerability is fixed. No other official remediation or temporary fix is indicated. Users should avoid opening untrusted EPUB, OPF, or PDF files in vulnerable versions until patched.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-06-09T17:30:33.455Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a4d6893c9d9e3dbe3d5457a
Added to database: 07/07/2026, 20:58:59 UTC
Last enriched: 07/15/2026, 11:59:47 UTC
Last updated: 08/21/2026, 11:03:56 UTC
Views: 90
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