# Sitecore CMS and Experience Platform (XP): 2 exploited vulnerabilities (CVE-2019-9874, CVE-2019-9875) · pwn.watch

> CVE-2019-9874: Sitecore CMS and Experience Platform (XP) contain a deserialization vulnerability in the Sitecore.Security.AntiCSRF module that allows an unauthenticated attacker to execute arbitrary code by sending a serialized .NET object in the HTTP POST parameter __CSRFTOKEN. CVE-2019-9875: Sitecore CMS and Experience Platform (XP) contain a deserialization vulnerability in the Sitecore.Security.AntiCSRF module that allows an authenticated attacker to execute arbitrary code by sending a serialized .NET object in the HTTP POST parameter __CSRFTOKEN. Added to CISA KEV on 2025-03-26.

Page: https://pwn.watch/i/sitecore-cms-and-experience-platform-xp-cve-2019-9874 · generated 2026-10-22T20:45:43.249Z

## Status
- Severity: critical · status: closed · patch: patched
- Product: Sitecore CMS and Experience Platform (XP)
- Started: 2025-03-26 · closed: 2025-03-26
- CVEs: CVE-2019-9874, CVE-2019-9875
- Affected: See vendor advisory / CISA notes (versions not always listed in KEV feed)
- Fixed in: See vendor advisory linked in sources

## Follow this incident
- RSS (one item per update): https://pwn.watch/i/sitecore-cms-and-experience-platform-xp-cve-2019-9874/feed.xml
- JSON Feed: https://pwn.watch/i/sitecore-cms-and-experience-platform-xp-cve-2019-9874/feed.json
- Full data (timeline, sources, posts, agentBrief): https://pwn.watch/i/sitecore-cms-and-experience-platform-xp-cve-2019-9874.json
- This file: https://pwn.watch/i/sitecore-cms-and-experience-platform-xp-cve-2019-9874/llms.txt

## Updates (newest first)
- 2025-03-26: CISA added CVE-2019-9874 to the KEV catalog (due 2025-04-16).
- 2025-03-26: CISA added CVE-2019-9875 to the KEV catalog (due 2025-04-16).

## Fix brief
# Security brief: Sitecore CMS and Experience Platform (XP): 2 exploited vulnerabilities (CVE-2019-9874, CVE-2019-9875)

Source: https://pwn.watch/i/sitecore-cms-and-experience-platform-xp-cve-2019-9874 · status: closed (closed Mar 26, 2025) · severity: critical · updated Mar 26, 2025

## Patch status
**PATCHED: fixed releases exist. Upgrade to a fixed version.**

## What it is
CVE-2019-9874: Sitecore CMS and Experience Platform (XP) contain a deserialization vulnerability in the Sitecore.Security.AntiCSRF module that allows an unauthenticated attacker to execute arbitrary code by sending a serialized .NET object in the HTTP POST parameter __CSRFTOKEN. CVE-2019-9875: Sitecore CMS and Experience Platform (XP) contain a deserialization vulnerability in the Sitecore.Security.AntiCSRF module that allows an authenticated attacker to execute arbitrary code by sending a serialized .NET object in the HTTP POST parameter __CSRFTOKEN. Added to CISA KEV on 2025-03-26.

Severity detail: CVSS 9.8 (CISA ADP, v3.1); actively exploited (CISA KEV)

- Product: Sitecore CMS and Experience Platform (XP)
- CVE / advisory ids: CVE-2019-9874, CVE-2019-9875

## Affected versions
- See vendor advisory / CISA notes (versions not always listed in KEV feed)

## Check whether you're affected
No generic command applies (the product is a hosted service, appliance or desktop app). Check the installed version in its admin UI / About screen and compare with the versions above.

## Fix
Upgrade to one of these fixed versions (or later on the same branch):
- See vendor advisory linked in sources

After upgrading, re-run the checks above and redeploy/restart the affected services.

## Secrets to rotate
This incident involves possible credential exposure. Rotate any credentials (API keys, tokens, env vars, SSH keys) that were present on affected systems or in affected builds while vulnerable/compromised versions were installed, and review access logs.

## Latest updates
- Mar 26, 2025: CISA added CVE-2019-9874 to the KEV catalog (due 2025-04-16).
- Mar 26, 2025: CISA added CVE-2019-9875 to the KEV catalog (due 2025-04-16).

## Advisories
- [Sitecore advisory: Sitecore CMS and Experience Platform (XP)](https://support.sitecore.com/kb?id=kb_article_view&sysparm_article=KB0334035) (Sitecore)
- [Sitecore advisory: Sitecore CMS and Experience Platform (XP)](https://support.sitecore.com/kb?id=kb_article_view&sysparm_article=KB0038556) (Sitecore)
- [NVD: CVE-2019-9874](https://nvd.nist.gov/vuln/detail/CVE-2019-9874) (NVD)
- [NVD: CVE-2019-9875](https://nvd.nist.gov/vuln/detail/CVE-2019-9875) (NVD)
- [CISA Known Exploited Vulnerabilities Catalog](https://www.cisa.gov/known-exploited-vulnerabilities-catalog) (CISA)

## Caveats
Derived from CISA KEV JSON feed catalogVersion 2026.10.21. CVSS from the CVE record (cvelistV5). Exact affected/fixed version strings are not always in the KEV record; verify against the vendor advisory URL. startedAt uses dateAdded (exploitation may have begun earlier; many entries are older CVEs newly confirmed as exploited in 2025).

---
Machine-readable: https://pwn.watch/i/sitecore-cms-and-experience-platform-xp-cve-2019-9874.json · all incidents: https://pwn.watch/incidents.json. Verify against the vendor advisory before changing production systems.