CVE-2026-26064: calibre-ebook calibre Path Traversal

Vulnerability summary

CVE-2026-26064 is a critical (CVSS 9.3) Path Traversal vulnerability in calibre-ebook calibre. EPSS estimates a 0.95% chance of exploitation in the next 30 days, higher than 60.6% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 20-02-2026
   PublishedVulnerability first disclosed.
2. 20-02-2026
   Last modifiedVulnerability information updated.

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.

• CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.