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CVE-2026-27026

MEDIUM

5.5

Description

pypdf is a free and open-source pure-python PDF library. Prior to 6.7.1, an attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires a malformed /FlateDecode stream, where the byte-by-byte decompression is used. This vulnerability is fixed in 6.7.1.

CVE Details

CVSS v3.1 Score5.5

SeverityMEDIUM

CVSS VectorCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Attack VectorLOCAL

ComplexityLOW

Privileges RequiredLOW

User InteractionNONE

Published2/20/2026

Last Modified2/24/2026

Sourcenvd

Honeypot Sightings0

Affected Products

pypdf_project:pypdf

Weaknesses (CWE)

CWE-770

References

https://github.com/py-pdf/pypdf/commit/7905842d833f899f1d3228af7e7467ad80277016(security-advisories@github.com)

https://github.com/py-pdf/pypdf/pull/3644(security-advisories@github.com)

https://github.com/py-pdf/pypdf/releases/tag/6.7.1(security-advisories@github.com)

https://github.com/py-pdf/pypdf/security/advisories/GHSA-9mvc-8737-8j8h(security-advisories@github.com)

IOC Correlations

No correlations recorded

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