CVE-2025-6069 — Regex Denial of Service in Software Foundation Cpython

CWE-1333 — Regex Denial of Service10 documents8 sources
Severity
4.3MEDIUMNVD
EPSS
0.9%
top 24.88%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
1
Python Software Foundation Cpython
Timeline
PublishedJun 17
Latest updateAug 29

Description

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

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:LExploitability: 2.8 | Impact: 1.4

Affected Packages1 packages

▶CVEListV5python_software_foundation/cpython3.10.0 — 3.10.19+5

🔴Vulnerability Details

5
OSV
python2.7 vulnerability↗2025-08-29
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OSV
python3.13, python3.12, python3.11, python3.10, python3.9, python3.8, python3.7, python3.6, python3.5, python3.4 vulnerabilities↗2025-08-21
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CVEList
HTMLParser quadratic complexity when processing malformed inputs↗2025-06-17
▶
OSV
CVE-2025-6069: The html↗2025-06-17
▶
GHSA
GHSA-j5cc-6rx8-ff96: The html↗2025-06-17
▶

📋Vendor Advisories

4
Ubuntu
Python vulnerabilities↗2025-08-21
▶
Red Hat
cpython: Python HTMLParser quadratic complexity↗2025-06-17
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Microsoft
HTMLParser quadratic complexity when processing malformed inputs↗2025-06-10
▶
Debian
CVE-2025-6069: jython - The html.parser.HTMLParser class had worse-case quadratic complexity when proces...↗2025
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CVE-2025-6069 — Regex Denial of Service | cvebase