---
title: "CVE-2025-53690: Sitecore Multiple Products Deserialization of Untrusted Data Vulnerability"
url: https://erroneo.us/security/cve/CVE-2025-53690/
description: "CVE-2025-53690 (Sitecore Multiple Products): Exploited in the wild (CISA KEV). Deserialization of Untrusted Data vulnerability in Sitecore Experience…"
type: vulnerability-record
section: "Security Digest"
date_published: 2025-09-03
date_modified: 2026-02-26
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2025-53690"
kev: true
cvss: 9
epss: 0.60601
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2025-53690: Sitecore Multiple Products Deserialization of Untrusted Data Vulnerability

**Signal:** Exploited: patch now if you run it. CISA has confirmed exploitation in the wild. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Yes, if you run Sitecore Multiple Products. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2025-09-04, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2025-09-25 ; treat that as the outer limit, not the target.
- EPSS 60.6% , percentile 99: FIRST’s model estimates a 60.6% chance of exploitation activity in the next 30 days, higher than 99% of all scored CVEs (very high). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.

## What it is

Deserialization of Untrusted Data vulnerability in Sitecore Experience Manager (XM), Sitecore Experience Platform (XP) allows Code Injection.This issue affects Experience Manager (XM): through 9.0; Experience Platform (XP): through 9.0.

## Affected products (CVE record)

- Sitecore Experience Manager (XM): <= 9.0
- Sitecore Experience Platform (XP): <= 9.0

## Severity

- Wiz CVSS 3.1: 9 `CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H`

## Exploitation

- CISA KEV: added 2025-09-04; federal due date 2025-09-25. Known ransomware use: Unknown.
- CISA required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- CISA SSVC assessment: exploitation active , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 60.60% probability of exploitation activity in the next 30 days; percentile 99.

## Sources

- [Listed in CISA KEV notes (support.sitecore.com)](https://support.sitecore.com/kb?id=kb_article_view&sysparm_article=KB1003865)
- [CVE.org record CVE-2025-53690](https://www.cve.org/CVERecord?id=CVE-2025-53690)
- [NVD entry CVE-2025-53690](https://nvd.nist.gov/vuln/detail/CVE-2025-53690)
- [CISA Known Exploited Vulnerabilities catalog entry](https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-53690)
- [cloud.google.com](https://cloud.google.com/blog/topics/threat-intelligence/viewstate-deserialization-zero-day-vulnerability)

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Source page: https://erroneo.us/security/cve/CVE-2025-53690/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt