PyPDF2 quadratic runtime with malformed PDF missing xref marker
Impact
An attacker who uses this vulnerability can craft a PDF which leads to unexpected long runtime. This quadratic runtime blocks the current process and can utilize a single core of the CPU by 100%. It does not affect memory usage.
Patches
https://github.com/py-pdf/pypdf/pull/808
Workarounds
Is there a way for users to fix or remediate the vulnerability without upgrading?
References
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Python (PyPI) | pypdf2 | < 1.27.9 | 1.27.9 |
References
- https://github.com/py-pdf/pypdf/security/advisories/GHSA-jrm6-h9cq-8gqw
- https://nvd.nist.gov/vuln/detail/CVE-2023-36810
- https://github.com/py-pdf/pypdf/issues/582
- https://github.com/py-pdf/pypdf/pull/808
- https://github.com/py-pdf/pypdf/commit/c6c56f550bb384e05f0139c796ba1308837d6373
- https://github.com/py-pdf/pypdf
- https://lists.debian.org/debian-lts-announce/2023/07/msg00019.html
- https://pypi.org/project/pypdf2
- https://github.com/advisories/GHSA-jrm6-h9cq-8gqw
- CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H- Weakness (CWE)
CWE-407- Platform
- Python (PyPI)
- Package
pypdf2- Disclosed
- 30.06.2023
- Updated
- 11.10.2026 13:19
Sources and licenses
OSV / GitHub Advisory Database - PYSEC-2026-1837 - PyPA Advisory Database; CC BY 4.0
OSV / GitHub Advisory Database - GHSA-jrm6-h9cq-8gqw - CC BY 4.0
Vulnerability history: pypdf2
All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 4
- First → latest
- 04.2022 06.2023
- Without a fix
- 1
- Exploited in attacks
- 0
Severity breakdown
- Medium 4
Disclosures per year
- 2022: 1
- 2023: 3
- 2024: 0
- 2025: 0
- 2026: 0
-
PyPDF2 quadratic runtime with malformed PDF missing xref marker this entry
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