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MEDIUM

CVE-2025-6069

CVSS v3

4.3

MEDIUM

EPSS Score

0.6 %

exploit probability, as of 2026-10-19

CISA KEV

No

known exploited

Exploitation

—

SSVC status

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Affected and fixed versions

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • pythonBitnamiall versions · fixed in 3.9.24and 2 other packages
  • python3AlmaLinux:9all versions · fixed in 3.9.25-2.el9_7and 7 other packages
  • python39AlmaLinux:8all versions · fixed in 3.9.25-2.module_el8.10.0+4083+53cad1fband 7 other packages
  • python39-attrsAlmaLinux:8all versions · fixed in 20.3.0-2.module_el8.6.0+2780+a40f65e1
  • python39-cffiAlmaLinux:8all versions · fixed in 1.14.3-2.module_el8.6.0+3248+c431e88c
  • python39-chardetAlmaLinux:8all versions · fixed in 3.0.4-19.module_el8.6.0+2780+a40f65e1
  • python39-cryptographyAlmaLinux:8all versions · fixed in 3.3.1-3.module_el8.10.0+3765+2f9a457d
  • python39-CythonAlmaLinux:8all versions · fixed in 0.29.21-5.module_el8.6.0+3248+c431e88c

30 more package ranges on OSV.dev

Vendor advisories

  • CVE-2025-6069 Red Hat Product Security391 products fixed · 121 known affected

    cpython: Python HTMLParser quadratic complexity

    python-unversioned-command as a component of Red Hat Enterprise Linux 10 · python3 as a component of Red Hat Enterprise Linux 10 · python3-debug as a component of Red Hat Enterprise Linux 10

  • RHSA-2026:76945 Red Hat Product Security40 products fixed

    Red Hat Security Advisory: python3.9 security update

  • RHSA-2026:74087 Red Hat Product Security40 products fixed

    Red Hat Security Advisory: python3.9 security update

  • RHSA-2026:1858 Red Hat Product Security3 products fixed

    Red Hat Security Advisory: Red Hat Ceph Storage

  • RHSA-2026:1652 Red Hat Product Security4 products fixed

    Red Hat Security Advisory: Red Hat Ceph Storage

  • RHSA-2026:0685 Red Hat Product Security4 products fixed

    Red Hat Security Advisory: Red Hat Update Infrastructure 5 security update

3 more advisories

Full record on NVD

Description

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

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
Published
2025-06-17
Last Modified
2026-04-15

Frequently asked questions

What is CVE-2025-6069?

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

Is CVE-2025-6069 actively exploited?

Active exploitation of CVE-2025-6069 has not been confirmed. Its EPSS score was 0.6% on 2026-10-19, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2025-6069?

CVE-2025-6069 has a CVSS v3 base score of 4.3 (MEDIUM severity), with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L.

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