CVE-2019-9875
Sitecore CMS and Experience Platform (XP) Deserialization Vulnerability
Does this matter?
Known to be exploited in the wild (CISA KEV, CISA remediation deadline 16 April 2025). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.
Description
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.
- CVSS 3.1
- 8.8 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 25.44% probability · 98th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Listed 26 March 2025 · due 16 April 2025
- Weakness
- CWE-502
- Affected
- sitecore/cms
- Source
- cve@mitre.org
EPSS moved from 25.4% on 25 October 2026 to 25.4% on 26 October 2026. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”.
CISA notes
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. https://support.sitecore.com/kb?id=kb_article_view&sysparm_article=KB0038556 ; https://nvd.nist.gov/vuln/detail/CVE-2019-9875
References
- https://dev.sitecore.net/Downloads.aspxProduct, Vendor Advisory
- https://www.synacktiv.com/blog.htmlThird Party Advisory
- https://www.synacktiv.com/ressources/advisories/Sitecore_CSRF_deserialize_RCE.pdfExploit, Patch, Third Party Advisory
- https://dev.sitecore.net/Downloads.aspxProduct, Vendor Advisory
- https://www.synacktiv.com/blog.htmlThird Party Advisory
- https://www.synacktiv.com/ressources/advisories/Sitecore_CSRF_deserialize_RCE.pdfExploit, Patch, Third Party Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2019-9875US Government Resource
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.