High severity · published Apr 15, 2026
CVE-2025-40899
Stored Cross-Site Scripting (XSS) in Assets and Nodes in Guardian/CMC before 26.0.0
8.9
CVSS
0.3%
EPSS
No
On KEV
Description
A Stored Cross-Site Scripting vulnerability was discovered in the Assets and Nodes functionality due to improper validation of an input parameter. An authenticated user with custom fields privileges can define a malicious custom field containing a JavaScript payload. When the victim views the Assets or Nodes pages, the XSS executes in their browser context, allowing the attacker to perform unauthorized actions as the victim, such as modify application data, disrupt application availability, and access limited sensitive information.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
Required
Confidentiality
Low
Integrity
High
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 21% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CM
CMC · Nozomi Networks
before 26.0.0 · source: vendor
GU
Guardian · Nozomi Networks
before 26.0.0 · source: vendor
RA
RUGGEDCOM APE1808 · Siemens
0 · source: CISA
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-40899
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-40899
security.nozominetworks.com
https://security.nozominetworks.com/NN-2026:2-01
cert-portal.siemens.com
https://cert-portal.siemens.com/productcert/html/ssa-827968.html
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