{"id":"CVE-2026-86433","aliases":["DEBIAN-CVE-2026-86433","EUVD-2026-72391","GHSA-f9pm-gcpp-fwjp","UBUNTU-CVE-2026-86433"],"status":"published","title":"commonmark 1.5.0 before 2.8.4 Denial of Service via Attributes","description":"commonmark versions from 1.5.0 before 2.8.4 contain a denial of service vulnerability in the Attributes extension where AttributesListener::findTargetAndDirection() performs quadratic-time sibling list scanning. Unauthenticated attackers can submit approximately 32 KB of repeated attribute blocks to cause parsing to take over 5 seconds, exhausting server resources.","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":0.00509,"percentile":0.43989,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-407"],"published":"2026-09-07T12:53:52Z","modified":"2026-10-09T09:47:25Z","fixes":[{"ecosystem":"Debian:14","package":"php-league-commonmark","fixed_in":["2.9.0-1"],"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":"2.9.0-1"}]}],"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"]},{"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-g2gp-3wwq-f4ph","tags":["vendor-advisory","report"]},{"url":"https://www.vulncheck.com/advisories/commonmark-1.5.0-before-2.8.4-denial-of-service-via-attributes","tags":["third-party-advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-86433"},{"url":"https://github.com/advisories/GHSA-f9pm-gcpp-fwjp"},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-86433","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2026-86433","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-86433","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-86433","title":"commonmark 1.5.0 before 2.8.4 Denial of Service via Attributes","description":"commonmark versions from 1.5.0 before 2.8.4 contain a denial of service vulnerability in the Attributes extension where AttributesListener::findTargetAndDirection() performs quadratic-time sibling list scanning. Unauthenticated attackers can submit approximately 32 KB of repeated attribute blocks to cause parsing to take over 5 seconds, exhausting server resources.","status":"published","published":"2026-09-07T12:53:52.562Z","modified":"2026-10-08T15:25:53.98Z","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-2026-72391","description":"commonmark versions from 1.5.0 before 2.8.4 contain a denial of service vulnerability in the Attributes extension where AttributesListener::findTargetAndDirection() performs quadratic-time sibling list scanning. Unauthenticated attackers can submit approximately 32 KB of repeated attribute blocks to cause parsing to take over 5 seconds, exhausting server resources.","status":"published","published":"2026-09-07T12:53:52Z","modified":"2026-10-08T15:25:53Z","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-f9pm-gcpp-fwjp","title":"commonmark versions from 1.5.0 before 2.8.4 contain a denial of service vulnerability in the...","description":"commonmark versions from 1.5.0 before 2.8.4 contain a denial of service vulnerability in the Attributes extension where AttributesListener::findTargetAndDirection() performs quadratic-time sibling list scanning. Unauthenticated attackers can submit approximately 32 KB of repeated attribute blocks to cause parsing to take over 5 seconds, exhausting server resources.","status":"published","published":"2026-09-07T15:33:53Z","modified":"2026-09-07T15:34:02Z","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-2026-86433","description":"commonmark versions from 1.5.0 before 2.8.4 contain a denial of service vulnerability in the Attributes extension where AttributesListener::findTargetAndDirection() performs quadratic-time sibling list scanning. Unauthenticated attackers can submit approximately 32 KB of repeated attribute blocks to cause parsing to take over 5 seconds, exhausting server resources.","status":"published","published":"2026-09-07T13:20:42.733Z","modified":"2026-10-08T16:17:57.81Z","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":"DEBIAN-CVE-2026-86433","description":"commonmark versions from 1.5.0 before 2.8.4 contain a denial of service vulnerability in the Attributes extension where AttributesListener::findTargetAndDirection() performs quadratic-time sibling list scanning. Unauthenticated attackers can submit approximately 32 KB of repeated attribute blocks to cause parsing to take over 5 seconds, exhausting server resources.","status":"published","published":"2026-09-07T13:20:42.733Z","modified":"2026-10-09T09:47:25.267003553Z","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-2026-86433","description":"commonmark versions from 1.5.0 before 2.8.4 contain a denial of service vulnerability in the Attributes extension where AttributesListener::findTargetAndDirection() performs quadratic-time sibling list scanning. Unauthenticated attackers can submit approximately 32 KB of repeated attribute blocks to cause parsing to take over 5 seconds, exhausting server resources.","status":"published","published":"2026-09-07T13:20:00Z","modified":"2026-09-16T14:03:21.052054922Z","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"}]}}