CVE-2026-27026

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.

CVSS v3 5.5 MEDIUM

5.5^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 1.8 / Impact : 3.6

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/py-pdf/pypdf/commit/7905842d833f899f1d3228af7e7467ad80277016	Patch
https://github.com/py-pdf/pypdf/pull/3644	Issue Tracking Patch
https://github.com/py-pdf/pypdf/releases/tag/6.7.1	Product Release Notes
https://github.com/py-pdf/pypdf/security/advisories/GHSA-9mvc-8737-8j8h	Patch Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:pypdf_project:pypdf:*:*:*:*:*:*:*:*

History

24 Feb 2026, 15:13

Type	Values Removed	Values Added
References	~~() https://github.com/py-pdf/pypdf/commit/7905842d833f899f1d3228af7e7467ad80277016 -~~	() https://github.com/py-pdf/pypdf/commit/7905842d833f899f1d3228af7e7467ad80277016 - Patch
References	~~() https://github.com/py-pdf/pypdf/pull/3644 -~~	() https://github.com/py-pdf/pypdf/pull/3644 - Issue Tracking, Patch
References	~~() https://github.com/py-pdf/pypdf/releases/tag/6.7.1 -~~	() https://github.com/py-pdf/pypdf/releases/tag/6.7.1 - Product, Release Notes
References	~~() https://github.com/py-pdf/pypdf/security/advisories/GHSA-9mvc-8737-8j8h -~~	() https://github.com/py-pdf/pypdf/security/advisories/GHSA-9mvc-8737-8j8h - Patch, Vendor Advisory
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 5.5
CPE		cpe:2.3:a:pypdf_project:pypdf::::::::
First Time		Pypdf Project Pypdf Project pypdf

20 Feb 2026, 22:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-02-20 22:16

Updated : 2026-02-24 15:13

NVD link : CVE-2026-27026

Mitre link : CVE-2026-27026

CVE.ORG link : CVE-2026-27026

JSON object : View

Products Affected

pypdf_project

pypdf

CWE

CWE-770

Allocation of Resources Without Limits or Throttling

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