CVE-2026-82398

pypdf is a free and open-source pure-python PDF library. Prior to 6.15.0, an attacker can craft a PDF that causes long runtimes when the pypdf/_utils.py function read_until_whitespace reads a stream containing a long run of bytes without whitespace. The function repeatedly performs immutable bytes concatenation in a one-byte loop, causing quadratic processing cost for the long non-whitespace input. This issue is fixed in version 6.15.0.

CVSS v3 5.3 MEDIUM

5.3^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 3.9 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact LOW

Scope UNCHANGED

References

Link	Resource
https://github.com/py-pdf/pypdf/commit/4959848e057e37c218dccad7465259210923faaa	Patch
https://github.com/py-pdf/pypdf/pull/3947	Patch
https://github.com/py-pdf/pypdf/releases/tag/6.15.0	Release Notes
https://github.com/py-pdf/pypdf/security/advisories/GHSA-fc8x-2rww-xw9m	Patch Vendor Advisory

Configurations

Configuration 1 (hide)

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

History

05 Oct 2026, 17:41

Type	Values Removed	Values Added
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 5.3
References	~~() https://github.com/py-pdf/pypdf/commit/4959848e057e37c218dccad7465259210923faaa -~~	() https://github.com/py-pdf/pypdf/commit/4959848e057e37c218dccad7465259210923faaa - Patch
References	~~() https://github.com/py-pdf/pypdf/pull/3947 -~~	() https://github.com/py-pdf/pypdf/pull/3947 - Patch
References	~~() https://github.com/py-pdf/pypdf/releases/tag/6.15.0 -~~	() https://github.com/py-pdf/pypdf/releases/tag/6.15.0 - Release Notes
References	~~() https://github.com/py-pdf/pypdf/security/advisories/GHSA-fc8x-2rww-xw9m -~~	() https://github.com/py-pdf/pypdf/security/advisories/GHSA-fc8x-2rww-xw9m - Patch, Vendor Advisory
First Time		Pypdf Project Pypdf Project pypdf
CPE		cpe:2.3:a:pypdf_project:pypdf::::::::

Information

Published : 2026-08-31 22:17

Updated : 2026-10-05 17:41

NVD link : CVE-2026-82398

Mitre link : CVE-2026-82398

CVE.ORG link : CVE-2026-82398

JSON object : View

Products Affected

pypdf_project

pypdf

CWE

CWE-407

Inefficient Algorithmic Complexity

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