Experience Manager (XM): Deserialization of Untrusted Data
CVE-2025-53691 is a high-severity deserialization of untrusted data vulnerability in Experience Manager (XM) from Sitecore, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected Experience Manager (XM) versions: 9.0 through 9.3; 10.0 through 10.4. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.64% chance of exploitation within 30 days, higher than 77% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Experience Platform to 10.4 or a later version.
- Read the advisory on support.sitecore.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Sitecore | Experience Manager (XM) | 9.0 through 9.3; 10.0 through 10.4 | Not stated |
| Sitecore | Experience Platform (XP) | 9.0 through 9.3; 10.0 through 10.4 | Not stated |
| Sitecore | Experience Commerce | 9.0 through 10.4 | Not stated |
| Sitecore | Experience Manager | 9.0 through 10.4 | Not stated |
| Sitecore | Experience Platform | 9.0 up to, but not including, 10.4; 10.4 | 10.4 |
| Sitecore | Managed Cloud | Not specified in the record | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA.
Official description
Deserialization of Untrusted Data vulnerability in Sitecore Experience Manager (XM), Sitecore Experience Platform (XP) allows Remote Code Execution (RCE).This issue affects Experience Manager (XM): from 9.0 through 9.3, from 10.0 through 10.4; Experience Platform (XP): from 9.0 through 9.3, from 10.0 through 10.4.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Deserialization of Untrusted Data
The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.
How developers prevent this class of flaw
- If available, use the signing/sealing features of the programming language to assure that deserialized data has not been tainted. For example, a hash-based message authentication code (HMAC) could be used to ensure that data has not been modified.
- When deserializing data, populate a new object rather than just deserializing. The result is that the data flows through safe input validation and that the functions are safe.
- Explicitly define a final object() to prevent deserialization.
More Deserialization of Untrusted Data vulnerabilities (CWE-502)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Technical write-ups (may include proof of concept)
- labs.watchtowr.com/cache-me-if-you-can-sitecore-experience-platform-cache-poisoning-to-rce/Exploit, Third Party Advisory
Other vulnerabilities in Experience Manager (XM)
- 9.0 Critical severity
- 8.7 High severity
Recent Deserialization of Untrusted Data vulnerabilities
- 7.8 High severity
- 7.2 High severity
- 7.2 High severity
- 7.2 High severity
- 8.8 High severity
- 7.8 High severity
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