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Vulnerability · Published Oct 29, 2026 · Assigned by GitHub_M

CVE-2026-119204pypdf: Possible large memory usage when parsing page tree

High 7.1

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 0.2% (higher than 13% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)7.1High
Exploit odds (30 days)0.2%top 87.3% 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 6.21.4, pypdf can consume excessive memory while parsing a crafted PDF page tree containing many shared resources. Page-tree flattening copies page dictionary and inherited resource entries without a document-wide entry budget, allowing the crafted resource structure to cause disproportionate allocations. This issue is fixed in version 6.21.4.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12pypdfno fix listedDEBIAN-CVE-2026-119204
Debian:13pypdfno fix listedDEBIAN-CVE-2026-119204
Debian:14pypdf6.21.4-1DEBIAN-CVE-2026-119204
Debian:12pypdf2no fix listedDEBIAN-CVE-2026-119204
PyPIpypdf6.21.4GHSA-cggf-277g-3q54
Ubuntu:24.04:LTSpypdfno fix listedUBUNTU-CVE-2026-119204
Ubuntu:26.04:LTSpypdfno fix listedUBUNTU-CVE-2026-119204
Ubuntu:26.10pypdfno fix listedUBUNTU-CVE-2026-119204

Affected products (as reported)

VendorProductVersions
py-pdf pypdf < 6.21.4

Weakness: CWE-400 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

References