| Package | Affected versions | Patched versions |
|---|---|---|
| pypdf | < 6.6.0 | 6.6.0 |
| pypdf | < 6.6.0 | 6.6.0 |
An attacker who exploits this vulnerability can craft a PDF which leads to possibly long runtimes for invalid startxref entries. When rebuilding the cross-reference table, PDF files with lots of whitespace characters become problematic. Only the non-strict reading mode is affected.
This has been fixed in pypdf==6.6.0.
from pypdf import PdfReader, PdfWriter
# Instead of
reader = PdfReader("file.pdf")
# use the strict mode:
reader = PdfReader("file.pdf", strict=True)
# Instead of
writer = PdfWriter(clone_from="file.pdf")
# use an explicit strict reader:
writer = PdfWriter(clone_from=PdfReader("file.pdf", strict=True))
This issue has been fixed in #3594.
Running one of these products? Scan your site to see whether it exposes a vulnerable version.
Scan my site free