CVE-2025-40891 HTML injection in in Time Machine functionality in Guardian/CMC before 25.5.0
Unauthenticated attackers can inject HTML into snapshot attributes, enabling phishing and open redirects when victims view specific diffs in the Time Machine feature.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2025-40891?
CVE-2025-40891 is a low-severity cross-site scripting vulnerability in Nozomi Networks CMC, published on 18 Dec 2025. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
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.
Weakness: CWE-79
Which versions are affected by CVE-2025-40891?
It affects 2 products.
Products include Nozominetworks Cmc, Nozominetworks Guardian.
How do I fix CVE-2025-40891?
No fix has been published for CVE-2025-40891 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2025-40891 being exploited?
There is no known exploitation of CVE-2025-40891 in the wild and no public exploit code.
Other vulnerabilities in Nozomi Networks CMC
- CVE-2023-29245 SQL Injection on IDS parsing of malformed asset fields in Guardian/CMC >= 22.6.0 before 22.6.3 and 23.1.0
- CVE-2026-31984 DoS through oversized audit log entries in Guardian/CMC before 26.2.0
- CVE-2023-2567 Authenticated SQL Injection on Query functionality in Guardian/CMC before 22.6.3 and 23.1.0
- CVE-2023-22378 Authenticated Blind SQL Injection on sorting in Guardian/CMC before 22.6.2
- CVE-2023-23574 Authenticated Blind SQL Injection on alerts count in Guardian/CMC before 22.6.2
Sources
Also known as GHSA-q3xp-m695-72w5.