CVE-2025-6069 MEDIUM

CVE-2025-6069: HTMLParser quadratic complexity when processing malformed inputs

Vendor Python Software Foundation
Product CPython
Weakness CWE-1333
Published June 17, 2025
Last update April 21, 2026
View on NVD All CVEs

CVSS base score

4.3/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality None
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

What the vulnerability does

01Description

The html.parser.HTMLParser class had worse-case quadratic complexity when processing certain crafted malformed inputs potentially leading to amplified denial-of-service.

Key dates

02Disclosure timeline

June 17, 2025 CVE published
April 21, 2026 Record updated