PyMuPDF up to 1.28.2 Font Branch src/__main__.py extract_objects path traversal

Summaryinfo

A vulnerability was found in PyMuPDF up to 1.28.2 and classified as critical. This affects the function extract_objects of the file src/__main__.py of the component Font Branch. The manipulation results in path traversal. This vulnerability is known as CVE-2026-82035. It is possible to launch the attack remotely. No exploit is available. Applying a patch is advised to resolve this issue.

Detailsinfo

A vulnerability, which was classified as critical, was found in PyMuPDF up to 1.28.2. Affected is the function extract_objects of the file src/__main__.py of the component Font Branch. The manipulation with an unknown input leads to a path traversal vulnerability. CWE is classifying the issue as CWE-22. 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. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

PyMuPDF through 1.28.2, fixed in commit b2c8f3a, contains a path traversal vulnerability in the font branch of extract_objects() in src/__main__.py, where the output filename is constructed by joining a document-controlled BaseFont name directly onto the user-supplied output directory without stripping path separators or dot-dot sequences. Attackers can supply a crafted PDF, EPUB, XPS, or FB2 file with a BaseFont name containing encoded path separators that decode to ../ sequences or absolute paths, causing arbitrary file writes outside the intended output directory without requiring authentication or elevated privileges.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-82035 since 08/27/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Successful exploitation requires user interaction by the victim. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1006.

Applying the patch b2c8f3a859fed35c379a44df566f770dc3e18605 is able to eliminate this problem.

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Productinfo

Type

• Document Reader Software

Name

• PyMuPDF

Version

• 1.28.0
• 1.28.1
• 1.28.2

Website

• Product: https://github.com/pymupdf/PyMuPDF/

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