CVE-2019-9875 Sitecore CMS and Experience Platform (XP): unsafe data loading
In plain words: The program unpacks saved data from outside without checking it is safe. Usually lets an attacker run code on the server.
Confirmed exploited by CISA on · US federal patch deadline Apr 16, 2025
What to do
- Install Sitecore's security update for CMS and Experience Platform (XP). If no update exists, follow the vendor's workaround or stop using the product until one ships.
- Keep a list of every internet-facing server you run so nothing is forgotten.
- Patch anything in this catalog first, ahead of normal patch cycles.
- Put admin and file-transfer apps behind a VPN or single sign-on instead of the open internet.
Who is affected
Work IT. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.
What's at risk: Mass data theft and ransomware: a single flaw in a file-transfer or email server has exposed thousands of organisations at once.
The details
- Official name
- Sitecore CMS and Experience Platform (XP) Deserialization Vulnerability
- Product
- Sitecore CMS and Experience Platform (XP)
- CISA description
- 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.
- Type of flaw
- Unsafe data loading (CWE-502)
- Confirmed exploited
- Mar 26, 2025
- US federal patch deadline
- Apr 16, 2025
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Answering about CVE-2019-9875 ·
Questions about CVE-2019-9875
Is CVE-2019-9875 being exploited?
Yes. CISA added CVE-2019-9875 to its Known Exploited Vulnerabilities catalog on Mar 26, 2025, which means there is reliable evidence of real-world attacks.
How do I fix CVE-2019-9875?
Install Sitecore's security update for CMS and Experience Platform (XP). If no update exists, follow the vendor's workaround or stop using the product until one ships. Keep a list of every internet-facing server you run so nothing is forgotten.
Am I affected by CVE-2019-9875?
Only if you use Sitecore CMS and Experience Platform (XP). Aimed mostly at company systems — you are affected through the companies you use, not your own phone.