CVE-2019-9875
Sitecore CMS and Experience Platform (XP) Deserialization Vulnerability
Sitecore CMS and Experience Platform (XP)
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.
Exploitation status
CISA Known Exploited Vulnerabilities
Listed by CISA on 26 March 2025. US federal agencies were required to remediate it by 16 April 2025.
EPSS — exploitation probability
FIRST puts the probability of exploitation activity in the next 30 days at 25.4%, which is higher than 98% of all scored vulnerabilities. EPSS is a forecast of activity, not a measure of severity, and it is rescored daily.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Frequently asked questions
Is CVE-2019-9875 being exploited by ransomware groups?
No ransomware group in this database is currently recorded as exploiting CVE-2019-9875.
What does CVE-2019-9875 affect?
CVE-2019-9875 affects Sitecore CMS and Experience Platform (XP). 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.
How severe is CVE-2019-9875?
CVE-2019-9875 is rated HIGH with a CVSS base score of 8.8. EPSS puts the probability of exploitation in the next 30 days at 25.4%, higher than 98% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 16 April 2025.
How should organisations respond to CVE-2019-9875?
Apply the vendor patch for Sitecore CMS and Experience Platform (XP) as the first priority, and treat any internet-facing instance as the most urgent. Because this vulnerability is associated with ransomware activity, also review whether the affected systems were reachable before patching, rather than assuming that patching alone closes the incident.