nmap-mcp-server: Improper Neutralization of Special Elements used in a Command
CVE-2026-3484 is a high-severity improper neutralization of special elements used in a command vulnerability in nmap-mcp-server from PhialsBasement, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected nmap-mcp-server versions: bee6d23547d57ae02460022f7c78ac0893092e38. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 3.3% chance of exploitation within 30 days, higher than 89% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of nmap-mcp-server you run against the affected versions below, and install the vendor's latest release.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| PhialsBasement | nmap-mcp-server | bee6d23547d57ae02460022f7c78ac0893092e38 | Not stated |
| Phialsbasement | Mcp Nmap Server | 1.0.1 and earlier | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 5.3 | Medium | CNA (vuldb.com) |
| CVSS 3.1 | 6.3 | Medium | CNA (vuldb.com) |
| CVSS 3.1 | 8.8 | High | NVD |
| CVSS 2.0 | 6.5 | Medium | CNA (vuldb.com) |
Official description
A vulnerability was detected in PhialsBasement nmap-mcp-server up to bee6d23547d57ae02460022f7c78ac0893092e38. Affected by this issue is the function child_process.exec of the file src/index.ts of the component Nmap CLI Command Handler. The manipulation results in command injection. The attack may be performed from remote. This product utilizes a rolling release system for continuous delivery, and as such, version information for affected or updated releases is not disclosed. The patch is identified as 30a6b9e1c7fa6146f51e28d6ab83a2568d9a3488. It is best practice to apply a patch to resolve this issue.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of Special Elements used in a Command
The product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component.
How developers prevent this class of flaw
- If at all possible, use library calls rather than external processes to recreate the desired functionality.
- If possible, ensure that all external commands called from the program are statically created.
- Run time: Run time policy enforcement may be used in an allowlist fashion to prevent use of any non-sanctioned commands.
More Improper Neutralization of Special Elements used in a Command vulnerabilities (CWE-77)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Third-party and government advisories
- vuldb.com/?id.348559Third Party Advisory, VDB Entry
- vuldb.com/?submit.763773Third Party Advisory, VDB Entry
- vuldb.com/?submit.763777Third Party Advisory, VDB Entry
Technical write-ups (may include proof of concept)
- github.com/PhialsBasement/nmap-mcp-server/issues/7Exploit, Issue Tracking
- github.com/PhialsBasement/nmap-mcp-server/issues/7#issuecomment-3814382570Exploit, Issue Tracking
Other references
- github.com/PhialsBasement/nmap-mcp-server/Product
- vuldb.com/?ctiid.348559Permissions Required, VDB Entry
Recent Improper Neutralization of Special Elements used in a Command vulnerabilities
- 8.1 High severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
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