{"id":"UBUNTU-CVE-2026-88753","details":"A Regular-Expression Denial of Service (ReDoS) in the Markdown2. extract_metadata() function (lib/markdown2.py) of trentm markdown2 through v2.5.5 allows attackers to cause a Denial of Service (DoS) via a crafted Markdown document.","modified":"2026-10-17T13:01:15.759071587Z","published":"2026-10-16T00:00:00Z","upstream":["CVE-2026-88753"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-88753"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-88753"},{"type":"REPORT","url":"https://gist.github.com/NanaSec/354b4188bbd7f4105008c7b8be49b0ba"}],"affected":[{"package":{"name":"python-markdown2","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/python-markdown2?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.3.7-2"],"ecosystem_specific":{"binaries":[{"binary_version":"2.3.7-2","binary_name":"python3-markdown2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-88753.json"}},{"package":{"name":"python-markdown2","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/python-markdown2?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.3.10-1.1","2.4.1-1"],"ecosystem_specific":{"binaries":[{"binary_name":"python3-markdown2","binary_version":"2.4.1-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-88753.json"}},{"package":{"name":"python-markdown2","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/python-markdown2?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.4.1-1","2.4.11-1"],"ecosystem_specific":{"binaries":[{"binary_name":"python3-markdown2","binary_version":"2.4.11-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-88753.json"}},{"package":{"name":"python-markdown2","ecosystem":"Ubuntu:26.10","purl":"pkg:deb/ubuntu/python-markdown2?arch=source&distro=stonking"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.5.4-3"],"ecosystem_specific":{"binaries":[{"binary_name":"python3-markdown2","binary_version":"2.5.4-3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-88753.json"}},{"package":{"name":"python-markdown2","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/python-markdown2?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.4.11-1","2.5.4-2","2.5.4-3"],"ecosystem_specific":{"binaries":[{"binary_version":"2.5.4-3","binary_name":"python3-markdown2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-88753.json"}}],"schema_version":"1.9.0","severity":[{"type":"Ubuntu","score":"medium"}]}