CVE-2026-33206: calibre-ebook calibre Relative Path Traversal

Vulnerability summary

CVE-2026-33206 is a high (CVSS 8.2) Relative Path Traversal vulnerability in calibre-ebook calibre. EPSS estimates a 0.22% chance of exploitation in the next 30 days, higher than 11.5% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 27-03-2026
   PublishedVulnerability first disclosed.
2. 27-03-2026
   Last modifiedVulnerability information updated.

Description

calibre is a cross-platform e-book manager for viewing, converting, editing, and cataloging e-books. Prior to version 9.6.0, a path traversal vulnerability exists in Calibre' handling of images in Markdown and other similar text-based files allowing an attacker to include arbitrary files from the file system into the converted book. Additionally, missing authentication and server-side request forgery in the background-image endpoint in the ebook reader web view allow the files to be exfiltrated without additional interaction. Version 9.6.0 contains a fix.

• CWE-23Relative Path TraversalThe product uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize sequences such as ".." that can resolve to a location that is outside of that directory.