CVE-2021-42237
CriticalExploitedPublic exploitSitecore XP 7.5 Initial Release to Sitecore XP 8.2 Update-7 is vulnerable to an insecure deserialization attack where it is possible to achieve remote command execution on the machine.
Published Nov 5, 2021 · Updated Jul 9, 2026
Key Facts
Patch immediately- CVE-2021-42237 is a critical-severity vulnerability (CVSS 9.8 v3.1) affecting Experience Platform (Sitecore).
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Mar 25, 2022 and is known to be used in ransomware campaigns. Public exploit code is available.
- EPSS estimates a 98% probability of exploitation in the next 30 days.
- No fixed version is listed yet; check the vendor advisory for mitigations.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
9.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
98%
Higher than 99.9% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings, used by ransomware
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2021-42237 brief as a PDF
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Description
Sitecore XP 7.5 Initial Release to Sitecore XP 8.2 Update-7 is vulnerable to an insecure deserialization attack where it is possible to achieve remote command execution on the machine. No authentication or special configuration is required to exploit this vulnerability.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Mar 25, 2022 | Apr 15, 2022 | Known |
| Industry KEV feed | Mar 25, 2022 | Apr 15, 2022 | Known |
| CIRCL KEV | Mar 25, 2022 | Apr 15, 2022 | Known |
| ENISA EUVD | Mar 25, 2022 | n/a | Not reported |
Required action: Apply updates per vendor instructions.
Affected Products
24 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| Experience PlatformSitecore | 7.5, 7.5-update1, 7.5-update2, 8.0, 8.0-sp1, 8.0-update1, 8.0-update2, 8.0-update3 | n/a |
Timeline
Publicly disclosed
Nov 5, 2021
Added to CISA KEV
Mar 25, 2022
Added to Industry KEV feed
Mar 25, 2022
Added to CIRCL KEV
Mar 25, 2022
Added to ENISA EUVD
Mar 25, 2022
Last updated
Jul 9, 2026
Weakness Type
- CWE-502 Deserialization of Untrusted Data
References
- advisoryhttp://packetstormsecurity.com/files/164988/Sitecore-Experience-Platform-XP-Remote-Code-Execution.html
- advisoryhttp://sitecore.com
- advisoryhttps://support.sitecore.com/kb?id=kb_article_view&sysparm_article=KB1000776
- exploithttps://blog.assetnote.io/2021/11/02/sitecore-rce/
- exploitVulnCheck exploitation report
FAQ
Common Questions.
Sitecore XP 7.5 Initial Release to Sitecore XP 8.2 Update-7 is vulnerable to an insecure deserialization attack where it is possible to achieve remote command execution on the machine.
Affected: Experience Platform (Sitecore) versions 7.5, 7.5-update1, 7.5-update2, 8.0, 8.0-sp1, 8.0-update1, 8.0-update2, 8.0-update3. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Mar 25, 2022 and is known to be used in ransomware campaigns.
Yes. It was added on Mar 25, 2022 with a federal remediation due date of Apr 15, 2022.
Public exploit code is available.
No fixed version is listed yet; check the vendor advisory for mitigations.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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