CVE-2026-82398

pypdf: Inefficient handling of non-whitespace inputs in read_until_whitespace

Published Aug 31, 2026 CVSS 4.0 · 6.9 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-fc8x-2rww-xw9m pypdf: Inefficient handling of non-whitespace inputs in read_until_whitespace
History
Type Values Removed Values Added
CPEs cpe:2.3:a:pypdf_project:pypdf:*:*:*:*:*:*:*:* cpe:2.3:a:py-pdf:pypdf:*:*:*:*:*:*:*:*
Vendors & Products Pypdf Project
Pypdf Project pypdf
Type Values Removed Values Added
First Time appeared Pypdf Project
Pypdf Project pypdf
CPEs cpe:2.3:a:pypdf_project:pypdf:*:*:*:*:*:*:*:*
Vendors & Products Pypdf Project
Pypdf Project pypdf
Type Values Removed Values Added
Metrics ssvc

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

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

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

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Sep 1, 2026, 2:57 PM
Reserved
Aug 28, 2026, 10:00 PM
Status
Analyzed
Published
Aug 31, 2026, 10:17 PM
Modified
Nov 2, 2026, 4:06 PM
Severity
Moderate
Public date
Aug 31, 2026, 9:41 PM