CVE-2025-69534

python3.13: Python-Markdown version 3.8 contain a vulnerability where malformed HTML-like sequences can cause html.parser.HTMLPar...

CVE-2025-69534 is fixed in 28 products on 1 platform, first by RHSA-2026:20677, released March 5, 2026. It is not reported as exploited. Patch Radar priority: High.

High
CVSS
8.2
high
Exploitation
None reported
No vendor assessment
CISA KEV
Not listed
Not in the Known Exploited Vulnerabilities catalog
EPSS
0.0066
51st percentile

Python-Markdown version 3.8 contain a vulnerability where malformed HTML-like sequences can cause html.parser.HTMLParser to raise an unhandled AssertionError during Markdown parsing. Because Python-Markdown does not catch this exception, any application that processes attacker-controlled Markdown may crash. This enables remote, unauthenticated Denial of Service in web applications, documentation systems, CI/CD pipelines, and any service that renders untrusted Markdown. The issue was acknowledged by the vendor and fixed in version 3.8.1. This issue causes a remote Denial of Service in any application parsing untrusted Markdown, and can lead to Information Disclosure through uncaught exceptions.

Where it's fixed

ProductFixed inFixReleased
Linux
idle-python3.10 · Ubuntu 22.04.1 LTS (jammy) 3.10.12-1~22.04.16 idle-python3.10 3.10.12-1~22.04.16 Jul 7, 2026
idle-python3.12 · Ubuntu 24.04.5 LTS (noble) 3.12.3-1ubuntu0.15 idle-python3.12 3.12.3-1ubuntu0.15 Jul 7, 2026
libpython3.10 · Ubuntu 22.04.1 LTS (jammy) 3.10.12-1~22.04.16 libpython3.10 3.10.12-1~22.04.16 Jul 7, 2026
libpython3.10-minimal · Ubuntu 22.04.1 LTS (jammy) 3.10.12-1~22.04.16 libpython3.10-minimal 3.10.12-1~22.04.16 Jul 7, 2026
libpython3.10-stdlib · Ubuntu 22.04.1 LTS (jammy) 3.10.12-1~22.04.16 libpython3.10-stdlib 3.10.12-1~22.04.16 Jul 7, 2026
libpython3.10-testsuite · Ubuntu 22.04.1 LTS (jammy) 3.10.12-1~22.04.16 libpython3.10-testsuite 3.10.12-1~22.04.16 Jul 7, 2026
libpython3.12-minimal · Ubuntu 24.04.5 LTS (noble) 3.12.3-1ubuntu0.15 libpython3.12-minimal 3.12.3-1ubuntu0.15 Jul 7, 2026
libpython3.12-stdlib · Ubuntu 24.04.5 LTS (noble) 3.12.3-1ubuntu0.15 libpython3.12-stdlib 3.12.3-1ubuntu0.15 Jul 7, 2026
libpython3.12-testsuite · Ubuntu 24.04.5 LTS (noble) 3.12.3-1ubuntu0.15 libpython3.12-testsuite 3.12.3-1ubuntu0.15 Jul 7, 2026
libpython3.12t64 · Ubuntu 24.04.5 LTS (noble) 3.12.3-1ubuntu0.15 libpython3.12t64 3.12.3-1ubuntu0.15 Jul 7, 2026
pypy3 · Debian 14 8.0.0+dfsg-1 DEBIAN-CVE-2025-69534 Mar 5, 2026
python-Markdown · opensuse-leap 15.6 3.5.2-150600.3.3.1 SUSE-SU-2026:0846-1 Mar 6, 2026
python-markdown · RHEL 10 3.5.1-6.el10_0.1 RHSA-2026:20677 Mar 5, 2026
python-markdown · rocky 10 0:3.5.1-6.el10_2.1 RLSA-2026:19155 May 29, 2026
python-markdown · rocky 9 0:3.3.4-4.el9_8.2 RLSA-2026:19366 May 28, 2026
python3-markdown · RHEL 9 0:3.3.4-4.el9_8.2 RHSA-2026:19366 May 27, 2026
python3-markdown · almalinux 10 3.5.1-6.el10_2.1 ALSA-2026:19155 May 19, 2026
python3-markdown · almalinux 9 3.3.4-4.el9_8.2 ALSA-2026:19366 May 19, 2026
python3-markdown · amzn 2023 3.3.4-2.amzn2023.0.4 ALAS2023-2026-1492 Mar 16, 2026
python3-markdown · ol 10 0:3.5.1-6.el10_2.1 ELSA-2026-19155 Jul 16, 2026
python3-markdown · ol 9 0:3.3.4-4.el9_8.2 ELSA-2026-19366 Jun 23, 2026
python3.10 · Ubuntu 22.04.1 LTS (jammy) 3.10.12-1~22.04.16 python3.10 3.10.12-1~22.04.16 Jul 7, 2026
python3.10-examples · Ubuntu 22.04.1 LTS (jammy) 3.10.12-1~22.04.16 python3.10-examples 3.10.12-1~22.04.16 Jul 7, 2026
python3.10-full · Ubuntu 22.04.1 LTS (jammy) 3.10.12-1~22.04.16 python3.10-full 3.10.12-1~22.04.16 Jul 7, 2026
python3.10-minimal · Ubuntu 22.04.1 LTS (jammy) 3.10.12-1~22.04.16 python3.10-minimal 3.10.12-1~22.04.16 Jul 7, 2026
python3.10-nopie · Ubuntu 22.04.1 LTS (jammy) 3.10.12-1~22.04.16 python3.10-nopie 3.10.12-1~22.04.16 Jul 7, 2026
python3.10-venv · Ubuntu 22.04.1 LTS (jammy) 3.10.12-1~22.04.16 python3.10-venv 3.10.12-1~22.04.16 Jul 7, 2026
python3.11 · Debian 12.15 (bookworm) 3.11.2-6+deb12u9 DEBIAN-CVE-2025-69534 Mar 5, 2026
python3.12 · Ubuntu 24.04.5 LTS (noble) 3.12.3-1ubuntu0.15 python3.12 3.12.3-1ubuntu0.15 Jul 7, 2026
python3.12-examples · Ubuntu 24.04.5 LTS (noble) 3.12.3-1ubuntu0.15 python3.12-examples 3.12.3-1ubuntu0.15 Jul 7, 2026
python3.12-full · Ubuntu 24.04.5 LTS (noble) 3.12.3-1ubuntu0.15 python3.12-full 3.12.3-1ubuntu0.15 Jul 7, 2026
python3.12-minimal · Ubuntu 24.04.5 LTS (noble) 3.12.3-1ubuntu0.15 python3.12-minimal 3.12.3-1ubuntu0.15 Jul 7, 2026
python3.12-nopie · Ubuntu 24.04.5 LTS (noble) 3.12.3-1ubuntu0.15 python3.12-nopie 3.12.3-1ubuntu0.15 Jul 7, 2026
python3.12-venv · Ubuntu 24.04.5 LTS (noble) 3.12.3-1ubuntu0.15 python3.12-venv 3.12.3-1ubuntu0.15 Jul 7, 2026
python3.13 · Debian 13.5 (trixie) 3.13.4-1 DEBIAN-CVE-2025-69534 Mar 5, 2026

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