CVE-2026-26065: calibre: Path Traversal can Lead to Arbitrary File Write and Potential Code Execution

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.6% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-02-20 · updated 2026-06-17
Weakness: CWE-22

Description

calibre is a cross-platform e-book manager for viewing, converting, editing, and cataloging e-books. Versions 9.2.1 and below are vulnerable to Path Traversal through PDB readers (both 132-byte and 202-byte header variants) that allow arbitrary file writes with arbitrary extension and arbitrary content anywhere the user has write permissions. Files are written in 'wb' mode, silently overwriting existing files. This can lead to potential code execution and Denial of Service through file corruption. This issue has been fixed in version 9.3.0.

Affected products

kovidgoyal calibre: before 9.3.0 — fixed in 9.3.0

How to fix

Upgrade to a fixed version: kovidgoyal calibre 9.3.0. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2026-26065 or the next vulnerability affects your stack