CVE-2026-26064: calibre: Path Traversal Vulnerability Enables Arbitrary File Write and Remote Code Execution

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.0% 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 contain a Path Traversal vulnerability that allows arbitrary file writes anywhere the user has write permissions. On Windows, this leads to Remote Code Execution by writing a payload to the Startup folder, which executes on next login. Function extract_pictures only checks startswith('Pictures'), and does not sanitize '..' sequences. calibre's own ZipFile.extractall() in utils/zipfile.py does sanitize '..' via _get_targetpath(), but extract_pictures() bypasses this by using manual zf.read() + open(). 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

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