CVE-2026-73249: Kovidgoyal Calibre

High severity, CVSS 7.5. EPSS: 0.4% chance of exploitation in the next 30 days.

calibre is an e-book manager. Prior to 9.12.0, the calibre Content Server endpoint POST /book-update-annotations/{library_id}/{book_id}/{fmt} in src/calibre/srv/books.py omits needs_db_write=True, causing Router.dispatch() to skip ctx.check_for_write_access() before update_annotations() passes attacker-controlled JSON to db.merge_annotations_for_book(), which allows a readonly user or an anonymous user on an unauthenticated deployment to persist unauthorized book annotation changes. This issue is fixed in version 9.12.0.

Affected products

• Kovidgoyal Calibre: before 9.12.0 (fixed in 9.12.0)

Published 2026-08-11. Last modified 2026-09-09.