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Vulnerability · Published Feb 27, 2026 · Assigned by GitHub_M

CVE-2026-28351Manipulated RunLengthDecode streams can exhaust RAM

Medium 6.9

In plain English

A medium-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 0.5% (higher than 42% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)6.9Medium
Exploit odds (30 days)0.5%top 58.4% 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 version 6.7.4, an attacker who uses this vulnerability can craft a PDF which leads to large memory usage. This requires parsing the content stream using the RunLengthDecode filter. This has been fixed in pypdf 6.7.4. As a workaround, consider applying the changes from PR #3664.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12pypdfno fix listedDEBIAN-CVE-2026-28351
Debian:13pypdfno fix listedDEBIAN-CVE-2026-28351
Debian:14pypdf6.9.0-1DEBIAN-CVE-2026-28351
Debian:12pypdf2no fix listedDEBIAN-CVE-2026-28351
PyPIpypdf6.7.4GHSA-f2v5-7jq9-h8cg
PyPIpypdf6.7.4PYSEC-2026-3017
Ubuntu:24.04:LTSpypdfno fix listedUBUNTU-CVE-2026-28351
Ubuntu:25.10pypdfno fix listedUBUNTU-CVE-2026-28351
Ubuntu:26.04:LTSpypdfno fix listedUBUNTU-CVE-2026-28351
Ubuntu:26.10pypdfno fix listedUBUNTU-CVE-2026-28351
Ubuntu:22.04:LTSpypdf2no fix listedUBUNTU-CVE-2026-28351
Ubuntu:24.04:LTSpypdf2no fix listedUBUNTU-CVE-2026-28351

Affected products (as reported)

VendorProductVersions
py-pdf pypdf < 6.7.4

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

References