{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-77912", "assignerOrgId": "82327ea3-741d-41e4-88f8-2cf9e791e760", "state": "PUBLISHED", "assignerShortName": "GitHub_P", "dateReserved": "2026-08-21T17:43:37.308Z", "datePublished": "2026-09-22T20:43:56.061Z", "dateUpdated": "2026-09-22T20:43:56.061Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "82327ea3-741d-41e4-88f8-2cf9e791e760", "shortName": "GitHub_P", "dateUpdated": "2026-09-22T20:43:56.061Z"}, "title": "Stored cross-site scripting vulnerability in GitHub Enterprise Server allowed HTML attribute injection via the Markdown rendering pipeline", "problemTypes": [{"descriptions": [{"lang": "en", "cweId": "CWE-79", "description": "CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')", "type": "CWE"}]}], "impacts": [{"capecId": "CAPEC-592", "descriptions": [{"lang": "en", "value": "CAPEC-592 Stored XSS"}]}], "affected": [{"vendor": "GitHub", "product": "Enterprise Server", "versions": [{"status": "affected", "version": "3.17.0", "lessThan": "3.17.*", "changes": [{"at": "3.17.21", "status": "unaffected"}], "versionType": "semver"}, {"status": "affected", "version": "3.18.0", "lessThan": "3.18.*", "changes": [{"at": "3.18.15", "status": "unaffected"}], "versionType": "semver"}, {"status": "affected", "version": "3.19.0", "lessThan": "3.19.*", "changes": [{"at": "3.19.12", "status": "unaffected"}], "versionType": "semver"}, {"status": "affected", "version": "3.20.0", "lessThan": "3.20.*", "changes": [{"at": "3.20.8", "status": "unaffected"}], "versionType": "semver"}, {"status": "affected", "version": "3.21.0", "lessThan": "3.21.*", "changes": [{"at": "3.21.6", "status": "unaffected"}], "versionType": "semver"}, {"status": "affected", "version": "3.22.0", "lessThan": "3.22.*", "changes": [{"at": "3.22.1", "status": "unaffected"}], "versionType": "semver"}], "defaultStatus": "unknown"}], "descriptions": [{"lang": "en", "value": "A stored cross-site scripting (XSS) vulnerability was identified in GitHub Enterprise Server that allowed an authenticated attacker to inject arbitrary HTML attributes into rendered Markdown because the Markdown rendering pipeline rewrote quote characters in already-sanitized HTML without re-sanitizing the result. 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{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[3.17.0,3.17.21)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[3.17.21,3.18.0)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[3.18.0,3.18.15)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[3.18.15,3.19.0)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[3.19.0,3.19.12)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[3.19.12,3.20.0)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[3.20.0,3.20.8)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[3.20.8,3.21.0)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[3.21.0,3.21.6)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[3.21.6,3.22.0)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[3.22.0,3.22.1)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[3.22.1,3.23.0)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Enterprise Server", "source": "cna", "vendor": "GitHub"}, "product": "enterprise_server", "vendor": "github"}], "created": "2026-09-22T23:15:15.915896+00:00", "updated": "2026-09-22T23:15:16.207297+00:00", "vendors": ["github", "github$PRODUCT$enterprise_server"]}