CVE-2026-25731: Calibre-Ebook Calibre

High severity, CVSS 7.8. EPSS: 0.3% chance of exploitation in the next 30 days.

calibre is an e-book manager. Prior to 9.2.0, a Server-Side Template Injection (SSTI) vulnerability in Calibre's Templite templating engine allows arbitrary code execution when a user converts an ebook using a malicious custom template file via the --template-html or --template-html-index command-line options. This vulnerability is fixed in 9.2.0.

Affected products

• Calibre-Ebook Calibre: before 9.2.0 (fixed in 9.2.0)

Published 2026-02-06. Last modified 2026-06-17.