CVE-2026-28351

low-risk
Published 2026-02-27

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.

Do I need to act?

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0.02% 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
5
CVSS 5.3/10 Medium
NETWORK / LOW complexity

Affected Products (1)

Affected Vendors

Pypdf Project

References (4)

Patch https://github.com/py-pdf/pypdf/commit/f309c6003746414dc7b5048c19e6d879ff2dc858
Issue Tracking https://github.com/py-pdf/pypdf/pull/3664
Release Notes https://github.com/py-pdf/pypdf/releases/tag/6.7.4
Patch https://github.com/py-pdf/pypdf/security/advisories/GHSA-f2v5-7jq9-h8cg
26
/ 100
low-risk
Severity 21/34 · High
Exploitability 0/34 · Minimal
Exposure 5/34 · Minimal