CVE-2025-55197

moderate-risk
Published 2025-08-13

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.

Do I need to act?

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0.10% chance of exploitation
EPSS score — low exploit probability
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Not on CISA KEV list
No confirmed active exploitation reported to CISA
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Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
7
CVSS 7.5/10 High
NETWORK / LOW complexity

Affected Products (1)

Affected Vendors

Pypdf Project

References (5)

Product https://github.com/py-pdf/pypdf/blob/0dd57738bbdcdb63f0fb43d8a6b3d222b6946595/py...
Issue Tracking https://github.com/py-pdf/pypdf/issues/3429
Patch https://github.com/py-pdf/pypdf/pull/3430
Release Notes https://github.com/py-pdf/pypdf/releases/tag/6.0.0
Mitigation https://github.com/py-pdf/pypdf/security/advisories/GHSA-7hfw-26vp-jp8m
31
/ 100
moderate-risk
Severity 26/34 · High
Exploitability 0/34 · Minimal
Exposure 5/34 · Minimal