{"schema_version":"1.9.0","id":"CVE-2025-69534","published":"2026-03-05T00:00:00Z","modified":"2026-09-09T03:31:04.216947801Z","aliases":["GHSA-5wmx-573v-2qwq","PYSEC-2026-89"],"related":["ALSA-2026:19155","ALSA-2026:19366","SUSE-SU-2026:0846-1"],"details":"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.","affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/python-markdown/markdown","events":[{"introduced":"b34e1d03387be771aa626241fe56f8f0c34243f2"},{"last_affected":"b34e1d03387be771aa626241fe56f8f0c34243f2"}],"database_specific":{"cpe":"cpe:2.3:a:python-markdown:markdown:3.8:*:*:*:*:python:*:*","extracted_events":[{"introduced":"3.8"},{"last_affected":"3.8"}],"source":"CPE_STRING"}}],"versions":["3.8"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-69534.json"}}],"references":[{"type":"WEB","url":"http://www.openwall.com/lists/oss-security/2026/03/06/4"},{"type":"WEB","url":"https://github.com/Python-Markdown/markdown/actions/runs/15736122892"},{"type":"WEB","url":"https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-69534.json"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:10184"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:13508"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:13512"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:13826"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:14835"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:14873"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:14874"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:19155"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:19366"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:20674"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:20676"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:20677"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:9742"},{"type":"ADVISORY","url":"https://access.redhat.com/security/cve/CVE-2025-69534"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/69xxx/CVE-2025-69534.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-69534"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2444839"},{"type":"REPORT","url":"https://github.com/Python-Markdown/markdown/issues/1534"},{"type":"PACKAGE","url":"https://github.com/Python-Markdown/markdown"}],"database_specific":{"cna_assigner":"mitre","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/69xxx/CVE-2025-69534.json"},"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}