HIGH8.7
PYSEC-2026-4153
pypdf: Possible long runtimes/large memory usage when parsing indirect objects
Quick fix
PYSEC-2026-4153 — pypdf: upgrade to the fixed version with the command below.
pip install --upgrade 'pypdf>=6.18.0'Details
### Impact
An attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires reading a PDF document with long indirect object headers, not terminated by whitespace.
### Patches
This has been fixed in [pypdf==6.18.0](https://github.com/py-pdf/pypdf/releases/tag/6.18.0).
### Workarounds
If you cannot upgrade yet, consider applying the changes from PR [#4055](https://github.com/py-pdf/pypdf/pull/4055).
Are you affected?
Enter the version of the package you're using.
Affected packages
References
- https://github.com/py-pdf/pypdf/security/advisories/GHSA-5jq2-8x83-x246[WEB]
- https://nvd.nist.gov/vuln/detail/CVE-2026-102994[ADVISORY]
- https://github.com/py-pdf/pypdf/pull/4055[WEB]
- https://github.com/py-pdf/pypdf/commit/82501d2993c6387833c4949d205caeb188f8bb9e[WEB]
- https://github.com/py-pdf/pypdf[PACKAGE]
- https://github.com/py-pdf/pypdf/releases/tag/6.18.0[WEB]
- https://pypi.org/project/pypdf[PACKAGE]
- https://github.com/advisories/GHSA-5jq2-8x83-x246[ADVISORY]