What is CVE-2019-9874?

CVE-2019-9874 is a critical-severity vulnerability in Sitecore Cms, classified under Deserialization of Untrusted Data. CVSS score: 9.8/10. Published 2019-05-31.

How severe is CVE-2019-9874?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Is CVE-2019-9874 known to be exploited?

Yes. CVE-2019-9874 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2025-03-26), indicating it is being actively exploited. 4 public proof-of-concept repositories are indexed.

Deserialization in Sitecore Cms

CVE-2019-9874

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.

Vulnerability class: Insecure Deserialization

Published 2019-05-31 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.837 (99.7th percentile), scored 2026-10-18.

High probability of exploitation in the next 30 days — patch promptly. 100th percentile — 99.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.837 · newest: 0.837 · change: 0.000

Affected products

Weakness classification (CWE)

CWE-502 — Deserialization of Untrusted Data

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on 2025-03-26. CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: 2025-04-16.

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.

Public proof-of-concept exploits

References

dev.sitecore.net/Downloads.aspx (Product, Vendor Advisory)
www.synacktiv.com/blog.html (Third Party Advisory)
www.synacktiv.com/ressources/advisories/Sitecore_CSRF_deserialize_RCE.pdf (Exploit, Patch, Third Party Advisory)
134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)

Frequently asked questions

What is CVE-2019-9874?: CVE-2019-9874 is a critical-severity vulnerability in Sitecore Cms, classified under Deserialization of Untrusted Data. CVSS score: 9.8/10. Published 2019-05-31.
How severe is CVE-2019-9874?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2019-9874 known to be exploited?: Yes. CVE-2019-9874 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2025-03-26), indicating it is being actively exploited. 4 public proof-of-concept repositories are indexed.