High CVSS 8.5
CVE-2026-53511
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.
What this means
- Exposure
- Exploitable with local access to the machine and without authentication — but only if a user opens booby-trapped content.
- Impact
- An attacker can read sensitive data, modify or destroy data and take the service offline.
- Weakness
- The application interprets attacker-supplied code, which then runs with its privileges.
- Likelihood
- Its EPSS score stays low: nothing points to imminent exploitation, which is no reason to leave it unpatched.
What to doFold into the next patch cycle.
Read automatically from the CVSS vector, the weakness type (CWE) and the EPSS score. The technical description above remains the one published by NIST.