CVE-2026-27026

5.5 MEDIUM
Published: February 20, 2026 Modified: February 24, 2026
View on NVD

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.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

References to Advisories, Solutions, and Tools

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

4 reference(s) from NVD

Quick Stats

CVSS v3 Score
5.5 / 10.0
EPSS (Exploit Probability)
0.0%
2th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

CWE-770

Affected Vendors

pypdf_project

Related CVEs

CVE-2026-2756 5.0
CVE-2019-25582 6.5
CVE-2019-25581 8.2
CVE-2019-25580 8.2
CVE-2019-25579 7.5