High 8.7Published Sep 30, 2026

CVE-2026-103000pypdf: Possible large memory usage when retrieving alphabetical page labels

Updated under an hour ago (2026-10-19 10:00 UTC)

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It affects py-pdf pypdf and 1 other product. Add what you run to find out whether that includes you.

EPSS puts the chance of exploitation in the next 30 days at 0.34%, higher than 26% of scored CVEs.

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Every CVE for py-pdf pypdf

Exploited in the last 30 days

pypdf is a free and open-source pure-python PDF library. Prior to 6.19.0, a crafted PDF can provide unusually large alphabetical page-label values that cause pypdf/_page_labels.py to generate strings beyond a reasonable page-label length when an application retrieves document page labels, consuming excessive memory and potentially making the application unavailable. This issue is fixed in version 6.19.0.

CVSS: 8.7 HIGH (v4.0, CNA)CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Weakness (CWE): CWE-400
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): 0.34% (percentile 26)
Assigned by: GitHub_M
NVD analysis: Analyzed
Record last updated: Sep 30, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

py-pdf pypdf py_pdf:pypdf (from the name)	before 6.19.0	CNA record
pypdf_project pypdf pypdf_project:pypdf	before 6.19.0	NVD

References

https://github.com/py-pdf/pypdf/security/advisories/GHSA-w23x-9jrw-r45cx-refsource-confirm, vendor-advisory
https://github.com/py-pdf/pypdf/pull/4096x-refsource-misc, patch, issue-tracking
https://github.com/py-pdf/pypdf/commit/0d8b5a8832cde1ba308b5c27567b879b7b7eed4ax-refsource-misc, patch
https://github.com/py-pdf/pypdf/releases/tag/6.19.0x-refsource-misc, release-notes

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.