CVE-2025-40891
MEDIUMNozomi Networks CMC and Guardian < 25.5.0 - Unauthenticated Stored HTML Injection via Time Machine Snapshot Diff
Title source: llmDescription
A Stored HTML Injection vulnerability was discovered in the Time Machine Snapshot Diff functionality due to improper validation of network traffic data. An unauthenticated attacker can send specially crafted network packets at two different times to inject HTML tags into asset attributes across two snapshots. Exploitation requires a victim to use the Time Machine Snapshot Diff feature on those specific snapshots and perform specific GUI actions, at which point the injected HTML renders in their browser, enabling phishing and open redirect attacks. Full XSS exploitation is prevented by input validation and Content Security Policy. Attack complexity is high due to multiple required conditions.
References (2)
Core 2
Core References
Vendor Advisory
https://security.nozominetworks.com/NN-2025:12-01
Vendor Advisory
https://cert-portal.siemens.com/productcert/html/ssa-827968.html
Scores
CVSS v3
4.7
EPSS
0.0014
EPSS Percentile
4.0%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
partial
Details
CWE
CWE-79
Status
published
Products (4)
Nozomi Networks/CMC
< 25.5.0
Nozomi Networks/Guardian
< 25.5.0
nozominetworks/cmc
< 25.5.0
nozominetworks/guardian
< 25.5.0
Published
Dec 18, 2025
Tracked Since
Feb 18, 2026