CVE-2026-33206 calibre has a path traversal vulnerability

What is CVE-2026-33206?

CVE-2026-33206 is a high-severity path traversal vulnerability in kovidgoyal calibre, published on 27 Mar 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

Official 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.

Weakness: CWE-23

Which versions are affected by CVE-2026-33206?

It affects 1 product.

Products include Calibre-Ebook Calibre.

How do I fix CVE-2026-33206?

Upgrade to a fixed version.

Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.

Is CVE-2026-33206 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-33206 exists.

Other vulnerabilities in kovidgoyal calibre

• CVE-2011-4124 Command injection in Calibre Critical 9.8
• CVE-2011-4125 Privilege escalation in Calibre Critical 9.8
• CVE-2026-26064 calibre: Path Traversal Vulnerability Enables Arbitrary File Write and Remote Code Execution Critical 9.3
• CVE-2026-26065 calibre: Path Traversal can Lead to Arbitrary File Write and Potential Code Execution Critical 9.3
• CVE-2026-25635 calibre has a Path Traversal Leading to Arbitrary File Write and Potential Code Execution High 8.6

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2026-33206, GHSA-h3p4-m74f-43g6, UBUNTU-CVE-2026-33206.