Vulnerability record

CVE-2019-9874

Sitecore CMS and Experience Platform (XP) Deserialization Vulnerability

CriticalExploitation confirmedCISA KEV

What should I do?

This vulnerability is in the CISA Known Exploited Vulnerabilities catalog: attackers are using it. If you run CMS and Experience Platform (XP), fix it now.

CISA required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

US federal civilian agencies must remediate by Apr 16, 2025.

Patch status

Official fix available since Sep 30, 2026

Apply the vendor's update to every affected system. Check the fixed-in versions below where known.

Basis: NVD patch reference

Patch or advisory on synacktiv.com (opens in a new tab)

Description

Deserialization of Untrusted Data in the Sitecore.Security.AntiCSRF (aka anti CSRF) module in Sitecore CMS 7.0 to 7.2 and Sitecore XP 7.5 to 8.2 allows an unauthenticated attacker to execute arbitrary code by sending a serialized .NET object in the HTTP POST parameter __CSRFTOKEN.

Source: NIST National Vulnerability Database. Official vulnerability data, reproduced as published.

Affected products

Products affected by this vulnerability, with versions and the source of each entry
Product	Vendor	Source
CMS and Experience Platform (XP)	Sitecore	KEV

Sources: KEV = CISA Known Exploited Vulnerabilities catalog. Version details have not been published yet.

Intelligence timeline

Developments from the last 30 days, newest first.

CVSS scoredUpdateKEVSep 30, 2026
CVE-2019-9874 scored CVSS 9.8: Sitecore CMS and Experience Platform (XP), Sitecore CMS and Experience Platform (XP) Deserialization Vulnerability
CISA lists this as exploited in the wild. Unpatched CMS and Experience Platform (XP) systems are exposed to active attacks now.
Basis: NIST National Vulnerability Database
Patch releasedUpdateKEVSep 30, 2026
Patch released for CVE-2019-9874: Sitecore CMS and Experience Platform (XP), Sitecore CMS and Experience Platform (XP) Deserialization Vulnerability
An official fix is now available for Sitecore CMS and Experience Platform (XP). This vulnerability is being exploited, so apply it promptly.
Basis: NVD patch reference

1 earlier event is available with a subscription. See plans.

Coverage

We have not published a story about this vulnerability yet.

References

support.sitecore.com https://support.sitecore.com/kb?id=kb_article_view&sysparm_article=KB0334035
nvd.nist.gov https://nvd.nist.gov/vuln/detail/CVE-2019-9874
dev.sitecore.net https://dev.sitecore.net/Downloads.aspx
synacktiv.com https://www.synacktiv.com/blog.html
synacktiv.com https://www.synacktiv.com/ressources/advisories/Sitecore_CSRF_deserialize_RCE.pdf
cisa.gov https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2019-9874