{"id":"CVE-2026-105829","state":"PUBLISHED","title":"League CommonMark 1.3.0 before 2.10.2 Stored XSS via DisallowedRawHtml Bypass","description":"League CommonMark from 1.3.0 before 2.10.2 contains a cross-site scripting vulnerability that allows users posting Markdown to bypass the DisallowedRawHtml extension by ending raw HTML with a bare disallowed tag name. Attackers can place a lone <script or <iframe line followed by a block supplying attributes like src or onload, executing stored scripts in viewers' browsers under default GFM settings.","publishedAt":"2026-10-08T14:10:30.523Z","updatedAt":"2026-10-10T03:05:39.203Z","severity":{"score":5.3,"label":"Medium","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N","source":"VulnCheck"},"assigner":"VulnCheck","products":["thephpleague commonmark"],"affected":[{"vendor":"thephpleague","product":"commonmark","packageURL":"pkg:composer/league/commonmark","defaultStatus":"unaffected"}],"references":["https://github.com/thephpleague/commonmark/security/advisories/GHSA-97jj-33gv-5xf9","https://www.vulncheck.com/advisories/league-commonmark-1.3.0-before-2.10.2-stored-xss-via-disallowedrawhtml-bypass"],"weaknesses":["CWE-80"],"ingestedAt":"2026-10-29T20:10:23.711Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/105xxx/CVE-2026-105829.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-105829","state":"PUBLISHED","datePublished":"2026-10-08T14:10:30.523Z","dateUpdated":"2026-10-10T03:05:39.203Z","assignerShortName":"VulnCheck","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateReserved":"2026-10-05T21:59:09.591Z"},"containers":{"cna":{"title":"League CommonMark 1.3.0 before 2.10.2 Stored XSS via DisallowedRawHtml Bypass","descriptions":[{"lang":"en","value":"League CommonMark from 1.3.0 before 2.10.2 contains a cross-site scripting vulnerability that allows users posting Markdown to bypass the DisallowedRawHtml extension by ending raw HTML with a bare disallowed tag name. Attackers can place a lone <script or <iframe line followed by a block supplying attributes like src or onload, executing stored scripts in viewers' browsers under default GFM settings."}],"affected":[{"vendor":"thephpleague","product":"commonmark","packageURL":"pkg:composer/league/commonmark","defaultStatus":"unaffected"}],"references":[{"url":"https://github.com/thephpleague/commonmark/security/advisories/GHSA-97jj-33gv-5xf9","tags":["vendor-advisory"],"name":"GitHub Security Advisory (GHSA-97jj-33gv-5xf9)"},{"url":"https://www.vulncheck.com/advisories/league-commonmark-1.3.0-before-2.10.2-stored-xss-via-disallowedrawhtml-bypass","name":"VulnCheck Advisory: League CommonMark 1.3.0 before 2.10.2 Stored XSS via DisallowedRawHtml Bypass","tags":["third-party-advisory"]}],"metrics":[{"format":"CVSS","cvssV4_0":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"PASSIVE","vulnConfidentialityImpact":"LOW","vulnIntegrityImpact":"LOW","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"LOW","subIntegrityImpact":"LOW","subAvailabilityImpact":"NONE","baseScore":5.3,"baseSeverity":"MEDIUM"}},{"format":"CVSS","cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"REQUIRED","scope":"CHANGED","confidentialityImpact":"LOW","integrityImpact":"LOW","availabilityImpact":"NONE","baseScore":6.1,"baseSeverity":"MEDIUM"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-80","lang":"en","description":"Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)","type":"CWE"}]}],"providerMetadata":{"shortName":"VulnCheck","orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateUpdated":"2026-10-08T15:22:12.780Z"},"datePublic":"2026-09-21T00:00:00.000Z","cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:thephpleague:commonmark:-:*:*:*:*:*:*:*"}]}]}],"credits":[{"lang":"en","value":"4n86rakam1","type":"reporter"}],"x_generator":{"engine":"vulncheck-endgame"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/thephpleague/commonmark/security/advisories/GHSA-97jj-33gv-5xf9","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-10T03:05:16.269227Z","id":"CVE-2026-105829","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-10T03:05:39.203Z"}}]}}}