CVE-2025-6069

HTMLParser quadratic complexity when processing malformed inputs

Published Jun 17, 2025 CVSS 3.1 · 4.3 Medium EPSS < 1% KEV · Not listed
Description
The html.parser.HTMLParser class had worse-case quadratic complexity when processing certain crafted malformed inputs potentially leading to amplified denial-of-service.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4354-1 pypy3 security update
Debian DLA Debian DLA DLA-4445-1 python3.9 security update
Debian DLA Debian DLA DLA-4458-1 python-django security update
Debian DLA Debian DLA DLA-4484-1 python-django security update
EUVD EUVD EUVD-2025-18496 The html.parser.HTMLParser class had worse-case quadratic complexity when processing certain crafted malformed inputs potentially leading to amplified denial-of-service.
Ubuntu USN Ubuntu USN USN-7710-1 Python vulnerabilities
History
Type Values Removed Values Added
References
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description The html.parser.HTMLParser class had worse-case quadratic complexity when processing certain crafted malformed inputs potentially leading to amplified denial-of-service.
Title HTMLParser quadratic complexity when processing malformed inputs
Weaknesses CWE-1333
References
Metrics cvssV3_1

{'score': 4.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
PSF
Published
Updated
Jul 31, 2026, 2:01 PM
Reserved
Jun 13, 2025, 2:05 PM
Status
Deferred
Published
Jun 17, 2025, 2:15 PM
Modified
Jul 31, 2026, 2:16 PM
Severity
Moderate
Public date
Jun 17, 2025, 1:39 PM