CVE-2026-22690
Medium
Description
pypdf is a free and open-source pure-python PDF library. Prior to version 6.6.0, pypdf has possible long runtimes for missing /Root object with large /Size values. An attacker who uses this vulnerability can craft a PDF which leads to possibly long runtimes for actually invalid files. This can be achieved by omitting the /Root entry in the trailer, while using a rather large /Size value. Only the non-strict reading mode is affected. This issue has been patched in version 6.6.0.
SeverityMedium
CVSS5.3
Exploit probability—
ProductPypdf
PublishedJan 10, 2026
First seenJan 10, 2026
Weakness typeCWE-400Uncontrolled resource consumption
How to fix
Update
- pypdf_project pypdf6.6.0 or later
- pypdf6.6.0 or later
- py-pdf pypdf6.6.0 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| pypdf_project pypdf | v < 6.6.0 | 6.6.0 |
| pypdfPyPI | v < 6.6.0 | 6.6.0 |
| py-pdf pypdf | v < 6.6.0 | 6.6.0 |
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