{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-104477", "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "state": "PUBLISHED", "assignerShortName": "VulnCheck", "dateReserved": "2026-10-02T00:55:58.388Z", "datePublished": "2026-10-02T23:28:47.414Z", "dateUpdated": "2026-10-02T23:28:47.414Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "shortName": "VulnCheck", "dateUpdated": "2026-10-02T23:28:47.414Z"}, "datePublic": "2026-06-27T00:00:00.000Z", "title": "Showdown through 2.1.0 XSS via unescaped quote in href and src attributes", "descriptions": [{"lang": "en", "value": "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 links or images containing a double quote followed by onerror or onmouseover handlers to execute script when victims view rendered HTML."}], "problemTypes": [{"descriptions": [{"lang": "en", "description": "Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')", "cweId": "CWE-79", "type": "CWE"}]}], "affected": [{"vendor": "showdownjs", "product": "showdown", "defaultStatus": "unaffected", "packageURL": "pkg:npm/showdown", "versions": [{"version": "0", "status": "affected", "versionType": "semver", "lessThanOrEqual": "2.1.0"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:showdownjs:showdown:*:*:*:*:*:*:*:*", "versionEndIncluding": "2.1.0"}]}]}], "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"}}], "references": [{"url": "https://github.com/showdownjs/showdown/commit/4fb992cd26631c108ec0410342630c80207ec7c6", "tags": ["patch"], "name": "Patch Commit"}, {"url": "https://github.com/showdownjs/showdown", "tags": ["product"]}, {"name": "VulnCheck Advisory: Showdown through 2.1.0 XSS via unescaped quote in href and src attributes", "tags": ["third-party-advisory"], "url": "https://www.vulncheck.com/advisories/showdown-through-2.1.0-xss-via-unescaped-quote-in-href-and-src-attributes"}], "credits": [{"lang": "en", "value": "Muhammad Sobirov", "type": "finder"}], "x_generator": {"engine": "vulncheck-endgame"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "packageURL": "pkg:npm/showdown", "product": "showdown", "vendor": "showdownjs", "versions": [{"lessThanOrEqual": "2.1.0", "status": "affected", "version": "0", "versionType": "semver"}]}], "source": "disclosure@vulncheck.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "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 links or images containing a double quote followed by onerror or onmouseover handlers to execute script when victims view rendered HTML."}], "id": "CVE-2026-104477", "lastModified": "2026-10-03T00:16:35.920", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 6.1, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "privilegesRequired": "NONE", "scope": "CHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N", "version": "3.1"}, "exploitabilityScore": 2.8, "impactScore": 2.7, "source": "disclosure@vulncheck.com", "type": "Primary"}], "cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 5.3, "baseSeverity": "MEDIUM", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "LOW", "subIntegrityImpact": "LOW", "userInteraction": "PASSIVE", "valueDensity": "NOT_DEFINED", "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/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", "version": "4.0", "vulnAvailabilityImpact": "NONE", "vulnConfidentialityImpact": "LOW", "vulnIntegrityImpact": "LOW", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "disclosure@vulncheck.com", "type": "Secondary"}]}, "published": "2026-10-03T00:16:35.920", "references": [{"source": "disclosure@vulncheck.com", "url": "https://github.com/showdownjs/showdown"}, {"source": "disclosure@vulncheck.com", "url": "https://github.com/showdownjs/showdown/commit/4fb992cd26631c108ec0410342630c80207ec7c6"}, {"source": "disclosure@vulncheck.com", "url": "https://www.vulncheck.com/advisories/showdown-through-2.1.0-xss-via-unescaped-quote-in-href-and-src-attributes"}], "sourceIdentifier": "disclosure@vulncheck.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-79"}], "source": "disclosure@vulncheck.com", "type": "Primary"}]}

{"bugzilla": {"description": "showdown: showdown: Cross-site scripting via unescaped double quotes in link and image attributes", "id": "2545432", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2545432"}, "csaw": false, "cvss3": {"cvss3_base_score": "6.1", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N", "status": "draft"}, "cwe": "CWE-79", "details": ["A flaw was found in showdown. The link and image parsers fail to properly sanitize or escape double quotation marks in destination URLs when rendering HTML attributes. A remote attacker could exploit this flaw by supplying crafted Markdown input containing malicious event handlers, leading to Cross-Site Scripting (XSS) and executing arbitrary script in the context of the victim's browser session."], "name": "CVE-2026-104477", "package_state": [{"cpe": "cpe:/a:redhat:multicluster_engine", "fix_state": "Out of support scope", "package_name": "multicluster-engine/console-mce-rhel9", "product_name": "Multicluster Engine for Kubernetes"}, {"cpe": "cpe:/a:redhat:workload_availability_nhc:0", "fix_state": "Out of support scope", "package_name": "workload-availability/node-healthcheck-must-gather-rhel9", "product_name": "Node HealthCheck Operator"}, {"cpe": "cpe:/a:redhat:workload_availability_nhc:0", "fix_state": "Out of support scope", "package_name": "workload-availability/node-healthcheck-operator-bundle", "product_name": "Node HealthCheck Operator"}, {"cpe": "cpe:/a:redhat:workload_availability_nhc:0", "fix_state": "Out of support scope", "package_name": "workload-availability/node-healthcheck-rhel9-operator", "product_name": "Node HealthCheck Operator"}, {"cpe": "cpe:/a:redhat:workload_availability_nhc:0", "fix_state": "Out of support scope", "package_name": "workload-availability/node-remediation-console-rhel8", "product_name": "Node HealthCheck Operator"}, {"cpe": "cpe:/a:redhat:red_hat_3scale_amp:2", "fix_state": "Out of support scope", "package_name": "3scale-amp2/system-rhel8", "product_name": "Red Hat 3scale API Management Platform 2"}, {"cpe": "cpe:/a:redhat:acm:2", "fix_state": "Out of support scope", "package_name": "rhacm2/console-rhel9", "product_name": "Red Hat Advanced Cluster Management for Kubernetes 2"}, {"cpe": "cpe:/a:redhat:ansible_automation_platform:2", "fix_state": "Out of support scope", "package_name": "automation-eda-controller", "product_name": "Red Hat Ansible Automation Platform 2"}, {"cpe": "cpe:/a:redhat:ansible_automation_platform:2", "fix_state": "Out of support scope", "package_name": "automation-gateway", "product_name": "Red Hat Ansible Automation Platform 2"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Fix deferred", "package_name": "rhoai/odh-core-bff-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Fix deferred", "package_name": "rhoai/odh-dashboard-operator-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Fix deferred", "package_name": "rhoai/odh-dashboard-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Fix deferred", "package_name": "rhoai/odh-mlflow-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Fix deferred", "package_name": "rhoai/odh-mod-arch-agent-ops-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Fix deferred", "package_name": "rhoai/odh-mod-arch-automl-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Fix deferred", "package_name": "rhoai/odh-mod-arch-autorag-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Fix deferred", "package_name": "rhoai/odh-mod-arch-eval-hub-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Fix deferred", "package_name": "rhoai/odh-mod-arch-gen-ai-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Fix deferred", "package_name": "rhoai/odh-mod-arch-maas-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Fix deferred", "package_name": "rhoai/odh-mod-arch-mlflow-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Fix deferred", "package_name": "rhoai/odh-mod-arch-model-registry-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Fix deferred", "package_name": "openshift4/ose-console", "product_name": "Red Hat OpenShift Container Platform 4"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Fix deferred", "package_name": "openshift4/ose-console-rhel9", "product_name": "Red Hat OpenShift Container Platform 4"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Fix deferred", "package_name": "openshift4/ose-monitoring-plugin-rhel8", "product_name": "Red Hat OpenShift Container Platform 4"}, {"cpe": "cpe:/a:redhat:container_native_virtualization:4", "fix_state": "Out of support scope", "package_name": "container-native-virtualization/kubevirt-console-plugin-rhel9", "product_name": "Red Hat OpenShift Virtualization 4"}, {"cpe": "cpe:/a:redhat:container_native_virtualization:4", "fix_state": "Out of support scope", "package_name": "openshift-virtualization/kubevirt-console-plugin", "product_name": "Red Hat OpenShift Virtualization 4"}, {"cpe": "cpe:/a:redhat:container_native_virtualization:4", "fix_state": "Fix deferred", "package_name": "openshift-virtualization/kubevirt-console-plugin-rhel9", "product_name": "Red Hat OpenShift Virtualization 4"}, {"cpe": "cpe:/a:redhat:quay:3", "fix_state": "Out of support scope", "package_name": "quay/quay-rhel8", "product_name": "Red Hat Quay 3"}, {"cpe": "cpe:/a:redhat:quay:3", "fix_state": "Fix deferred", "package_name": "quay/quay-rhel9", "product_name": "Red Hat Quay 3"}], "public_date": "2026-10-02T23:28:47Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-104477\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-104477\nhttps://github.com/showdownjs/showdown\nhttps://github.com/showdownjs/showdown/commit/4fb992cd26631c108ec0410342630c80207ec7c6\nhttps://www.vulncheck.com/advisories/showdown-through-2.1.0-xss-via-unescaped-quote-in-href-and-src-attributes"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[0,2.1.0]"}}], "enrichment": {"confidence": 90.0, "confidence_source": "inferred", "scores": [{"score": 90.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "showdown", "source": "cna", "vendor": "showdownjs"}, "product": "showdown", "vendor": "showdownjs"}], "created": "2026-10-03T00:30:19.410120+00:00", "updated": "2026-10-03T01:00:14.090970+00:00", "vendors": ["showdownjs", "showdownjs$PRODUCT$showdown"]}