CVE-2026-119203
High
Description
pypdf is a free and open-source pure-python PDF library. Prior to 6.21.4, pypdf can enter an infinite loop while opening a crafted incomplete PDF whose standard cross-reference table reaches the end of the file without a trailer. The trailer search can repeatedly rewind to the same stream position instead of terminating when parsing makes no progress, blocking the processing thread. This issue is fixed in version 6.21.4.
SeverityHigh
CVSS5.5
Exploit probability—
ProductPy-pdf Pypdf
PublishedOct 29, 2026
First seenNov 4, 2026
Weakness typeCWE-835CWE-835
How to fix
Update
- py-pdf pypdf6.21.4 or later
- pypdf6.21.4 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| py-pdf pypdf | v < 6.21.4 | 6.21.4 |
| pypdfPyPI | v < 6.21.4 | 6.21.4 |
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