PYSEC-2026-1834
See a problem?- Import Source
- https://github.com/pypa/advisory-database/blob/main/vulns/pypdf/PYSEC-2026-1834.yaml
- JSON Data
- https://api.osv.dev/v1/vulns/PYSEC-2026-1834
- Aliases
- Published
- 2026-07-07T11:45:26.634787Z
- Modified
- 2026-07-07T17:46:59.477344715Z
- Severity
-
- 5.1 (Medium) CVSS_V3 - CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
- Summary
- Possible Infinite Loop when PdfWriter(clone_from) is used with a PDF
- Details
-
Impact
An attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This infinite loop blocks the current process and can utilize a single core of the CPU by 100%. It does not affect memory usage.
That is, for example, the case when the pypdf-user manipulates an incoming malicious PDF e.g. by merging it with another PDF or by adding annotations.
Patches
The issue was fixed with #2264
Workarounds
If you cannot update your version of pypdf, you should modify
pypdf/generic/_data_structures.pyjust like #2264 did. - References
-
- https://github.com/py-pdf/pypdf/security/advisories/GHSA-wjcc-cq79-p63f
- https://nvd.nist.gov/vuln/detail/CVE-2023-46250
- https://github.com/py-pdf/pypdf/pull/2264
- https://github.com/py-pdf/pypdf/commit/9b23ac3c9619492570011d551d521690de9a3e2d
- https://github.com/py-pdf/pypdf
- https://pypi.org/project/pypdf
- https://github.com/advisories/GHSA-wjcc-cq79-p63f
Affected packages
PyPI / pypdf
Package
- Name
- pypdf
- View open source insights on deps.dev
- Purl
- pkg:pypi/pypdf