CVE-2026-103000GHSA-w23x-9jrw-r45cPYSEC-2026-4160
pypdf: Possible large memory usage when retrieving alphabetical page labels
py-pdf pypdfpipLibraries & packages
CVSS
8.7HighExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.34%Chance of exploitation activity in the next 30 days, higher than 26% of CVEs. Scored 23 Oct 2026FIRST EPSS
What fixes it
A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.
Description
Impact
An attacker who uses this vulnerability can craft a PDF which leads to large memory consumption. This requires accessing the page labels of a document with large alphabetical labels.
Patches
This has been fixed in pypdf==6.19.0.
Workarounds
If you cannot upgrade yet, consider applying the changes from PR #4096.
Text from GitHub Advisory Database
Affected versions 53
- pypdf, pip< 6.19.0GitHub
- pypdfaffected: < 6.19.0CVE List
- pypdf, PyPIfrom first release, fixed in 6.19.0OSV
- pypdf, PyPI1.0OSV
- pypdf, PyPI1.1OSV
- pypdf, PyPI1.10OSV
- pypdf, PyPI1.11OSV
- pypdf, PyPI1.12OSV
- pypdf, PyPI1.13OSV
- pypdf, PyPI1.2OSV
- pypdf, PyPI1.3OSV
- pypdf, PyPI1.4OSV
- pypdf, PyPI1.5OSV
- pypdf, PyPI1.6OSV
- pypdf, PyPI1.7OSV
- pypdf, PyPI1.8OSV
- pypdf, PyPI1.9OSV
- pypdf, PyPI3.1.0OSV
- pypdf, PyPI3.10.0OSV
- pypdf, PyPI3.11.0OSV
- pypdf, PyPI3.11.1OSV
- pypdf, PyPI3.12.0OSV
- pypdf, PyPI3.12.1OSV
- pypdf, PyPI3.12.2OSV
- pypdf, PyPI3.13.0OSV
- pypdf, PyPI3.14.0OSV
- pypdf, PyPI3.15.0OSV
- pypdf, PyPI3.15.1OSV
- pypdf, PyPI3.15.2OSV
- pypdf, PyPI3.15.3OSV
- pypdf, PyPI3.15.4OSV
- pypdf, PyPI3.15.5OSV
- pypdf, PyPI3.16.0OSV
- pypdf, PyPI3.16.1OSV
- pypdf, PyPI3.16.2OSV
- pypdf, PyPI3.16.3OSV
- pypdf, PyPI3.16.4OSV
- pypdf, PyPI3.17.0OSV
- pypdf, PyPI3.17.1OSV
- pypdf, PyPI3.17.2OSV
- pypdf, PyPI3.17.3OSV
- pypdf, PyPI3.17.4OSV
- pypdf, PyPI3.2.0OSV
- pypdf, PyPI3.2.1OSV
- pypdf, PyPI3.3.0OSV
- pypdf, PyPI3.4.0OSV
- pypdf, PyPI3.4.1OSV
- pypdf, PyPI3.5.0OSV
- pypdf, PyPI3.5.1OSV
- pypdf, PyPI3.5.2OSV
- pypdf, PyPI3.6.0OSV
- pypdf, PyPI3.7.0OSV
- pypdf, PyPI3.7.1OSV
References 6
- github.com/py-pdf/pypdf/commit/0d8b5a8832cde1ba308b5c27567b879b7b7eed4aFixvia CVE List
- github.com/py-pdf/pypdf/releases/tag/6.19.0Fixvia CVE List
- github.com/py-pdf/pypdf/security/advisories/GHSA-w23x-9jrw-r45cAdvisoryvia CVE List
- github.com/advisories/GHSA-w23x-9jrw-r45cAdvisoryvia GitHub
- nvd.nist.gov/vuln/detail/CVE-2026-103000Referencevia GitHub
- github.com/py-pdf/pypdf/pull/4096Referencevia CVE List