{"id":"CVE-2026-86428","aliases":["DEBIAN-CVE-2026-86428","EUVD-2026-72386","GHSA-8h74-w38m-j62j","UBUNTU-CVE-2026-86428"],"status":"published","title":"commonmark 1.5.0 before 2.10.0 Denial of Service via Attributes","description":"commonmark versions from 1.5.0 before 2.10.0 contain a denial of service vulnerability in the AttributesExtension when processing distinctly-named attributes. Attackers can submit Markdown with numerous distinct attribute names to cause quadratic-time attribute merging and filtering, consuming disproportionate CPU resources and preventing legitimate requests from completing.","severity":{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00493,"percentile":0.42868,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-407"],"published":"2026-09-07T12:53:49Z","modified":"2026-10-28T02:30:22Z","fixes":[{"ecosystem":"Debian:14","package":"php-league-commonmark","fixed_in":["2.10.0-1"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Debian:12","package":"php-league-commonmark","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.10.0-1","2.10.1-1","2.10.3-1","2.3.9-1","2.3.9-1+deb12u1","2.4.0-1","2.4.1-1","2.4.2-1","2.4.2-2","2.5.0-1","2.5.1-1","2.5.3-1","2.6.0-1","2.6.1-1","2.6.1-2","2.6.2-1","2.7.0-1","2.7.1-1","2.7.1-2","2.8.0-1","2.8.1-1","2.8.2-1","2.8.2-2","2.8.3-1","2.9.0-1"]},{"source":"osv","ecosystem":"Debian:13","package":"php-league-commonmark","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.10.0-1","2.10.1-1","2.10.3-1","2.7.0-1","2.7.0-1+deb13u1","2.7.1-1","2.7.1-2","2.8.0-1","2.8.1-1","2.8.2-1","2.8.2-2","2.8.3-1","2.9.0-1"]},{"source":"osv","ecosystem":"Debian:14","package":"php-league-commonmark","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.10.0-1"}]}],"versions":["2.7.0-1","2.7.1-1","2.7.1-2","2.8.0-1","2.8.1-1","2.8.2-1","2.8.2-2","2.8.3-1","2.9.0-1"]},{"source":"osv","ecosystem":"Ubuntu:Pro:20.04:LTS","package":"php-league-commonmark","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.1.2-1","1.2.0-1","1.3.0-1","1.3.1-1","1.3.1-1ubuntu2","1.3.1-1ubuntu2+esm1"]},{"source":"osv","ecosystem":"Ubuntu:Pro:22.04:LTS","package":"php-league-commonmark","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.5.7-2build1","1.6.6-1build1","1.6.7-1","1.6.7-1ubuntu0.1~esm1"]},{"source":"osv","ecosystem":"Ubuntu:Pro:24.04:LTS","package":"php-league-commonmark","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.3.9-1","2.4.1-1","2.4.2-1","2.4.2-2","2.4.2-2ubuntu0.1~esm1"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"php-league-commonmark","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.7.0-1","2.7.1-2","2.8.0-1"]}],"products":[{"vendor":"thephpleague","product":"commonmark"}],"references":[{"url":"https://github.com/thephpleague/commonmark/security/advisories/GHSA-8rr7-cvq3-gmfh","tags":["vendor-advisory","Mitigation","Vendor Advisory","advisory","report"]},{"url":"https://www.vulncheck.com/advisories/commonmark-1.5.0-before-2.10.0-denial-of-service-via-attributes","tags":["third-party-advisory","Third Party Advisory","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-86428","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-8h74-w38m-j62j"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/86xxx/CVE-2026-86428.json","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-86428","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2026-86428","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-86428","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-86428","title":"commonmark 1.5.0 before 2.10.0 Denial of Service via Attributes","description":"commonmark versions from 1.5.0 before 2.10.0 contain a denial of service vulnerability in the AttributesExtension when processing distinctly-named attributes. Attackers can submit Markdown with numerous distinct attribute names to cause quadratic-time attribute merging and filtering, consuming disproportionate CPU resources and preventing legitimate requests from completing.","status":"published","published":"2026-09-07T12:53:49.235Z","modified":"2026-10-08T15:25:50.773Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high","assessor":"cna"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-407"],"updated_at":"2026-11-02T13:49:42.666099Z"}],"euvd":[{"id":"EUVD-2026-72386","description":"commonmark versions from 1.5.0 before 2.10.0 contain a denial of service vulnerability in the AttributesExtension when processing distinctly-named attributes. Attackers can submit Markdown with numerous distinct attribute names to cause quadratic-time attribute merging and filtering, consuming disproportionate CPU resources and preventing legitimate requests from completing.","status":"published","published":"2026-09-07T12:53:49Z","modified":"2026-10-08T15:25:50Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high"}],"updated_at":"2026-11-02T17:27:28.564399Z"}],"ghsa":[{"id":"GHSA-8h74-w38m-j62j","title":"commonmark versions from 1.5.0 before 2.10.0 contain a denial of service vulnerability in the...","description":"commonmark versions from 1.5.0 before 2.10.0 contain a denial of service vulnerability in the AttributesExtension when processing distinctly-named attributes. Attackers can submit Markdown with numerous distinct attribute names to cause quadratic-time attribute merging and filtering, consuming disproportionate CPU resources and preventing legitimate requests from completing.","status":"published","published":"2026-09-07T15:33:53Z","modified":"2026-09-07T15:34:01Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-407"],"updated_at":"2026-11-02T15:11:27.182088Z"}],"nvd":[{"id":"CVE-2026-86428","description":"commonmark versions from 1.5.0 before 2.10.0 contain a denial of service vulnerability in the AttributesExtension when processing distinctly-named attributes. Attackers can submit Markdown with numerous distinct attribute names to cause quadratic-time attribute merging and filtering, consuming disproportionate CPU resources and preventing legitimate requests from completing.","status":"published","published":"2026-09-07T13:20:42.037Z","modified":"2026-10-08T16:17:56.837Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high","assessor":"secondary"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-407"],"updated_at":"2026-11-02T14:12:44.436435Z"}],"osv":[{"id":"CVE-2026-86428","title":"commonmark 1.5.0 before 2.10.0 Denial of Service via Attributes","description":"commonmark versions from 1.5.0 before 2.10.0 contain a denial of service vulnerability in the AttributesExtension when processing distinctly-named attributes. Attackers can submit Markdown with numerous distinct attribute names to cause quadratic-time attribute merging and filtering, consuming disproportionate CPU resources and preventing legitimate requests from completing.","status":"published","published":"2026-09-07T12:53:49.235Z","modified":"2026-10-28T02:30:22.611306085Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-407"],"updated_at":"2026-11-02T15:45:18.825071Z"},{"id":"DEBIAN-CVE-2026-86428","description":"commonmark versions from 1.5.0 before 2.10.0 contain a denial of service vulnerability in the AttributesExtension when processing distinctly-named attributes. Attackers can submit Markdown with numerous distinct attribute names to cause quadratic-time attribute merging and filtering, consuming disproportionate CPU resources and preventing legitimate requests from completing.","status":"published","published":"2026-09-07T13:20:42.037Z","modified":"2026-10-09T09:47:23.104264422Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high"}],"updated_at":"2026-11-02T15:46:05.022702Z"},{"id":"UBUNTU-CVE-2026-86428","description":"commonmark versions from 1.5.0 before 2.10.0 contain a denial of service vulnerability in the AttributesExtension when processing distinctly-named attributes. Attackers can submit Markdown with numerous distinct attribute names to cause quadratic-time attribute merging and filtering, consuming disproportionate CPU resources and preventing legitimate requests from completing.","status":"published","published":"2026-09-07T13:20:00Z","modified":"2026-09-16T14:03:38.055561049Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"},{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high"}],"updated_at":"2026-11-02T16:57:24.828975Z"}]}}