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Vulnerability · Published Sep 30, 2026 · Assigned by GitHub_M

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

High 8.7

In plain English

A high-severity uncontrolled resource consumption in pypdf from py-pdf. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 29% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)8.7High
Exploit odds (30 days)0.4%top 71.0% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12pypdfno fix listedDEBIAN-CVE-2026-103000
Debian:13pypdfno fix listedDEBIAN-CVE-2026-103000
Debian:14pypdf6.19.0-1DEBIAN-CVE-2026-103000
PyPIpypdf6.19.0PYSEC-2026-4160
PyPIpypdf6.19.0GHSA-w23x-9jrw-r45c
Ubuntu:24.04:LTSpypdfno fix listedUBUNTU-CVE-2026-103000
Ubuntu:26.04:LTSpypdfno fix listedUBUNTU-CVE-2026-103000
Ubuntu:26.10pypdfno fix listedUBUNTU-CVE-2026-103000
Ubuntu:22.04:LTSpypdf2no fix listedUBUNTU-CVE-2026-103000
Ubuntu:24.04:LTSpypdf2no fix listedUBUNTU-CVE-2026-103000

Affected products (as reported)

VendorProductVersions
py-pdf pypdf < 6.19.0

Weakness: CWE-400 · Vector: 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

References