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.
https://www.vulncheck.com/advisories/pymupdf-path-traversal-via-extract-objects-font-branch
https://github.com/pymupdf/PyMuPDF/commit/b2c8f3a859fed35c379a44df566f770dc3e18605
Published: 2026-09-14
Updated: 2026-09-14
Base Score: 8.5
Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:C/A:P
Severity: High
Base Score: 7.1
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:L
Severity: High
Base Score: 7.1
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N
Severity: High
EPSS: 0.00315