CVE-2025-2026: Moxa NPort 6100-G2/6200-G2 Series · Improper Null Termination
Affects Moxa NPort 6100-G2/6200-G2 SeriesSource CVE Database V5
Not known to be exploited · CVSS 7.1 High.
Data as of 25 Oct 2026, 19:02 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 35% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 31 Dec 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Moxa NPort 6100-G2/6200-G2 Series | Affected
| Fixed in– |
AI-suggested
1. Restrict network access to the web API interface of Moxa NPort 6100-G2/6200-G2 devices using network segmentation, firewalls, and access control lists to limit exposure to trusted management hosts only. 2. Enforce strong authentication and monitor for unauthorized access attempts to the device’s web interface, even for read-only accounts. 3. Implement continuous monitoring and alerting for unexpected device reboots or abnormal behavior indicative of exploitation attempts. 4. Coordinate with Moxa for timely firmware updates or patches addressing this vulnerability and apply them as soon as they become available. 5. Where possible, disable or limit web API functionalities that are not essential to reduce the attack surface. 6. Conduct regular security assessments and penetration tests on industrial control system networks to identify and remediate similar vulnerabilities. 7. Maintain an incident response plan that includes procedures for handling device outages caused by such vulnerabilities to minimize operational impact.
Description
CVE-2025-2026 is a high-severity vulnerability affecting Moxa NPort 6100-G2/6200-G2 Series devices. It involves improper null termination in the device’s web API, allowing authenticated remote attackers with read-only web privileges to perform null byte injection. Exploiting this flaw can cause the device to reboot unexpectedly, leading to a denial-of-service (DoS) condition. The vulnerability requires no user interaction and has a CVSS score of 7.1, indicating significant risk. Although no known exploits are currently in the wild, the impact on availability is substantial for operational environments relying on these devices. European organizations using these serial device servers in industrial or critical infrastructure settings could face operational disruptions. Mitigation involves restricting access to the web API, applying vendor patches when available, and monitoring device behavior for unexpected reboots. Countries with strong industrial automation sectors and critical infrastructure deployments of Moxa products, such as Germany, France, and the UK, are most likely to be affected.