CVE-2025-40891

CVE-2025-40891 is a medium-severity vulnerability in Nozominetworks Cmc with a CVSS 3.x base score of 4.7. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

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.

Frequently asked questions

What is CVE-2025-40891?
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.
How severe is CVE-2025-40891?
CVE-2025-40891 has a CVSS 3.x base score of 4.7, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2025-40891 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (4th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-40891?
CVE-2025-40891 primarily affects Nozominetworks Cmc. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2025-40891?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-40891 have an EU (EUVD) identifier?
Yes. CVE-2025-40891 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-204261.
When was CVE-2025-40891 published?
CVE-2025-40891 was published on 2025-12-18 and last updated on 2026-06-17.

References

Affected products (2)

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