CVE-2026-41313
Denial of Service via Large Trailer in pypdf Before
Publication date: 2026-04-22
Last updated on: 2026-04-27
Assigner: GitHub, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| pypdf_project | pypdf | to 6.10.2 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-834 | The product performs an iteration or loop without sufficiently limiting the number of times that the loop is executed. |
Attack-Flow Graph
AI Powered Q&A
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, you should upgrade pypdf to version 6.10.2 or later, where the issue has been fixed.
As a temporary workaround, you may manually apply the changes from the patch that fixes the vulnerability.
Can you explain this vulnerability to me?
The vulnerability exists in the pypdf library versions prior to 6.10.2. An attacker can craft a specially designed PDF file that contains a large trailer `/Size` value when loaded in incremental mode. This crafted PDF causes the library to experience long runtimes, potentially leading to performance degradation or denial of service.
This issue has been fixed in pypdf version 6.10.2, and as a workaround, users can manually apply the patch changes.
How can this vulnerability impact me? :
This vulnerability can impact you by causing long runtimes or performance issues when processing maliciously crafted PDF files using vulnerable versions of pypdf. This could lead to denial of service conditions or resource exhaustion on systems that automatically process PDFs.
How can this vulnerability be detected on my network or system? Can you suggest some commands?
This vulnerability affects pypdf versions prior to 6.10.2 when loading PDFs with a large trailer `/Size` value in incremental mode, causing long runtimes.
To detect if your system is vulnerable, first check the installed version of pypdf.
- Run the command: pip show pypdf
If the version is earlier than 6.10.2, your system may be vulnerable.
There are no specific network detection commands or signatures available from the provided information.