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.
History

Tue, 01 Sep 2026 22:00:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 01 Sep 2026 12:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-1046
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'}

threat_severity

Moderate


Mon, 31 Aug 2026 23:45:00 +0000

Type Values Removed Values Added
First Time appeared Py-pdf
Py-pdf pypdf
Vendors & Products Py-pdf
Py-pdf pypdf

Mon, 31 Aug 2026 21:45:00 +0000

Type Values Removed Values Added
Description 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.
Title pypdf: Inefficient handling of non-whitespace inputs in read_until_whitespace
Weaknesses CWE-407
References
Metrics cvssV4_0

{'score': 6.9, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-08-31T21:41:10.272Z

Updated: 2026-09-01T14:57:30.866Z

Reserved: 2026-08-28T22:00:43.512Z

Link: CVE-2026-82398

cve-icon Vulnrichment

Updated: 2026-09-01T14:18:27.524Z

cve-icon NVD

Status : Received

Published: 2026-08-31T22:17:23.083

Modified: 2026-09-01T15:17:32.697

Link: CVE-2026-82398

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-08-31T21:41:10Z

Links: CVE-2026-82398 - Bugzilla