{"id":"CVE-2026-104477","title":"Showdown through 2.1.0 contains a cross-site scripting vulnerability in the makehtml link and image subparsers, which fail to escape double quotes in destination URLs placed into href and src attributes","summary":"Showdown through 2.1.0 contains a cross-site scripting vulnerability in the makehtml link and image subparsers, which fail to escape double quotes in destination URLs placed into href and src attributes. Attackers can craft markdown link…","severity":"medium","cvss":6.1,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","cwe":["CWE-79"],"vendor":"showdownjs","product":"showdown","affected":["showdown <= 2.1.0"],"published":"2026-10-03","updated":"2026-10-06","sourceUpdated":"2026-10-06T16:00:36.547","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-104477","references":[{"url":"https://github.com/showdownjs/showdown","label":"disclosure@vulncheck.com"},{"url":"https://github.com/showdownjs/showdown/commit/4fb992cd26631c108ec0410342630c80207ec7c6","label":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/showdown-through-2.1.0-xss-via-unescaped-quote-in-href-and-src-attributes","label":"disclosure@vulncheck.com"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-104477.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-104477"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2545432"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-104477"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-104477"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"epss":0.00187,"epssPercentile":0.08263,"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"partial","timestamp":"2026-10-05T19:42:32.208544Z"},"ingestedAt":"2026-10-02T23:34:57.409Z","slug":"CVE-2026-104477","body":"## Overview\n\nShowdown through 2.1.0 contains a cross-site scripting vulnerability in the makehtml link and image subparsers, which fail to escape double quotes in destination URLs placed into href and src attributes. Attackers can craft markdown links or images containing a double quote followed by onerror or onmouseover handlers to execute script when victims view rendered HTML.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Cryostat 4, Multicluster Engine for Kubernetes, Node HealthCheck Operator, Red Hat 3scale API Management Platform 2, Red Hat Advanced Cluster Management for Kubernetes 2, Red Hat Ansible Automation Platform 2, … · no fix planned: Multicluster Engine for Kubernetes, Node HealthCheck Operator, Red Hat 3scale API Management Platform 2, Red Hat Advanced Cluster Management for Kubernetes 2, … · updated 2026-10-05 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-104477.json)","depth":"sunlit","depthScore":34,"depthScoreParts":{"impact":33.6,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}