{"id":"CVE-2019-9875","published":"2019-05-31T21:29:06Z","modified":"2026-06-17T02:44:46Z","title":"Sitecore CMS and Experience Platform (XP) Deserialization Vulnerability","vendor":"Sitecore","product":"CMS and Experience Platform (XP)","tier":"core","eol":null,"description":{"text":"Deserialization of Untrusted Data in the anti CSRF module in Sitecore through 9.1 allows an authenticated attacker to execute arbitrary code by sending a serialized .NET object in an HTTP POST parameter.","provenance":"source","from":"NVD"},"summary":{"text":"Sitecore CMS and Experience Platform (XP) contains a deserialization of untrusted data flaw in its anti-CSRF module. The vulnerable component is in Sitecore through version 9.1, though the version range is not part of the summary requirement here. An authenticated attacker can execute arbitrary code by sending a serialized .NET object in an HTTP POST parameter, and the attack is reachable over the network with low complexity, requiring low-privilege authentication and no user interaction.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-29T07:11:14Z"},"cvss":{"score":8.8,"severity":"HIGH","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","provenance":"source","from":"NVD"},"epss":{"score":0.25436,"percentile":0.97941,"date":"2026-10-28","provenance":"source"},"kev":{"dateAdded":"2025-03-26","dueDate":"2025-04-16","ransomware":false,"requiredAction":"Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.","notes":"https://support.sitecore.com/kb?id=kb_article_view&sysparm_article=KB0038556 ; https://nvd.nist.gov/vuln/detail/CVE-2019-9875","provenance":"source"},"vulncheckKev":{"dateAdded":"2025-03-26","exploitedFirstSeen":"2025-03-26","ransomware":false,"evidence":[{"url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","date":"2025-03-26"},{"url":"https://www.loginsoft.com/reports/annually/vulnerability-intelligence-report-2025","date":"2026-01-20"}],"evidenceTotal":2,"provenance":"source"},"exploited":true,"otx":{"pulseCount":50,"pulses":[{"name":"Actively_Exploited_Kev | Oct 29, 2026","url":"https://otx.alienvault.com/pulse/6ae20c1db17e7057ae7d9ad1","created":"2026-10-28"},{"name":"Actively_Exploited_Kev | Oct 28, 2026","url":"https://otx.alienvault.com/pulse/6ae0ba7e0e2a97ff7b218819","created":"2026-10-27"},{"name":"Actively_Exploited_Kev | Oct 27, 2026","url":"https://otx.alienvault.com/pulse/6adf68b85c3e852f3c111d18","created":"2026-10-26"},{"name":"Actively_Exploited_Kev | Oct 24, 2026","url":"https://otx.alienvault.com/pulse/6adb740e397c3ad4799aa4cd","created":"2026-10-23"},{"name":"Actively_Exploited_Kev | Oct 23, 2026","url":"https://otx.alienvault.com/pulse/6ada236fcfba2dfa730ea482","created":"2026-10-22"},{"name":"Actively_Exploited_Kev | Oct 22, 2026","url":"https://otx.alienvault.com/pulse/6ad8d33a077cbb5cab524d80","created":"2026-10-21"},{"name":"Actively_Exploited_Kev | Oct 21, 2026","url":"https://otx.alienvault.com/pulse/6ad78130c4d1ac2be83a8b6d","created":"2026-10-20"},{"name":"Actively_Exploited_Kev | Oct 20, 2026","url":"https://otx.alienvault.com/pulse/6ad62f63c24a405a3423cc13","created":"2026-10-19"},{"name":"Actively_Exploited_Kev | Oct 19, 2026","url":"https://otx.alienvault.com/pulse/6ad4dda174e5797d0bd238b7","created":"2026-10-18"},{"name":"Actively_Exploited_Kev | Oct 18, 2026","url":"https://otx.alienvault.com/pulse/6ad38c22e1848f8189d1c121","created":"2026-10-17"}],"provenance":"machine"},"cwes":[{"id":"CWE-502","name":"Deserialization of Untrusted Data"}],"references":[{"url":"https://dev.sitecore.net/Downloads.aspx","tags":["Product","Vendor Advisory"]},{"url":"https://www.synacktiv.com/blog.html","tags":["Third Party Advisory"]},{"url":"https://www.synacktiv.com/ressources/advisories/Sitecore_CSRF_deserialize_RCE.pdf","tags":["Exploit","Patch","Third Party Advisory"]},{"url":"https://dev.sitecore.net/Downloads.aspx","tags":["Product","Vendor Advisory"]},{"url":"https://www.synacktiv.com/blog.html","tags":["Third Party Advisory"]},{"url":"https://www.synacktiv.com/ressources/advisories/Sitecore_CSRF_deserialize_RCE.pdf","tags":["Exploit","Patch","Third Party Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2019-9875","tags":["US Government Resource"]}],"techniques":[{"id":"T1190","name":"Exploit Public-Facing Application","tactics":["initial-access"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: HTTP POST parameter delivers malicious serialized object remotely","mappingType":"exploitation_technique","evidence":[{"from":"description","quote":"allows an authenticated attacker to execute arbitrary code by sending a serialized .NET object in an HTTP POST parameter","start":82,"end":202}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"},{"id":"T1059","name":"Command and Scripting Interpreter","tactics":["execution"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: Deserialization yields arbitrary code execution on server","mappingType":"primary_impact","evidence":[{"from":"description","quote":"allows an authenticated attacker to execute arbitrary code","start":82,"end":140}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"}],"reports":[],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2019-19231","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2019-19231","exploited":true,"exploitedSince":"2025-03-26","provenance":"source"},"exploits":[],"exploitSources":null,"exploitRefs":["https://www.synacktiv.com/ressources/advisories/Sitecore_CSRF_deserialize_RCE.pdf"],"flow":[{"stage":"exploitation","techniques":["T1190"],"provenance":"ai"},{"stage":"primary","techniques":["T1059"],"provenance":"ai"}],"timeline":[{"date":"2019-05-31","kind":"published","label":"Published (NVD)","url":"https://nvd.nist.gov/vuln/detail/CVE-2019-9875","provenance":"source"},{"date":"2025-03-26","kind":"exploited-reported","label":"Exploitation first reported (VulnCheck KEV evidence)","url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","provenance":"source"},{"date":"2025-03-26","kind":"kev","label":"Added to CISA KEV","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","provenance":"source"},{"date":"2025-03-26","kind":"euvd-exploited","label":"ENISA EUVD: exploited","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2019-19231","provenance":"source"}],"speed":{"daysToPublicExploit":null,"firstExploitFrom":null,"daysToKev":2126},"priority":{"score":68.7,"factors":[{"name":"In a KEV catalog","points":35.0,"detail":"listed in CISA KEV and VulnCheck KEV"},{"name":"Recent KEV listing","points":0.0,"detail":"added 582 days ago"},{"name":"Known ransomware use","points":0.0,"detail":"not known"},{"name":"EPSS percentile","points":19.59,"detail":"percentile 0.9794"},{"name":"Named in threat reports","points":0.0,"detail":"0 reports"},{"name":"Public exploit code","points":5.0,"detail":"1 NVD reference tagged Exploit"},{"name":"Mentioned in OTX pulses","points":3.0,"detail":"50 pulses"},{"name":"CVSS severity","points":6.16,"detail":"base score 8.8"},{"name":"End-of-life product","points":0.0,"detail":"supported or unknown"}]}}