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Vulnerability · Published Aug 13, 2025 · Assigned by GitHub_M

CVE-2025-55197pypdf's Manipulated FlateDecode streams can exhaust RAM

Medium 6.6

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 43% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)6.6Medium
Exploit odds (30 days)0.5%top 56.5% 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 6.0.0, an attacker can craft a PDF which leads to the RAM being exhausted. This requires just reading the file if a series of FlateDecode filters is used on a malicious cross-reference stream. Other content streams are affected on explicit access. This issue has been fixed in 6.0.0. If an update is not possible, a workaround involves including the fixed code from pypdf.filters.decompress into the existing filters file.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12pypdfno fix listedDEBIAN-CVE-2025-55197
Debian:13pypdfno fix listedDEBIAN-CVE-2025-55197
Debian:14pypdf6.9.0-1DEBIAN-CVE-2025-55197
Debian:12pypdf2no fix listedDEBIAN-CVE-2025-55197
PyPIpypdf6.0.0GHSA-7hfw-26vp-jp8m
PyPIpypdf6.0.0PYSEC-2026-1830
Ubuntu:24.04:LTSpypdfno fix listedUBUNTU-CVE-2025-55197
Ubuntu:25.10pypdfno fix listedUBUNTU-CVE-2025-55197
Ubuntu:26.04:LTSpypdfno fix listedUBUNTU-CVE-2025-55197
Ubuntu:26.10pypdfno fix listedUBUNTU-CVE-2025-55197
Ubuntu:22.04:LTSpypdf2no fix listedUBUNTU-CVE-2025-55197
Ubuntu:24.04:LTSpypdf2no fix listedUBUNTU-CVE-2025-55197

Affected products (as reported)

VendorProductVersions
py-pdf pypdf < 6.0.0

Weakness: CWE-400, CWE-770 · 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/E:U

References