Full Report
Tenable security advisory (AV26-472)
Analysis Summary
# Vulnerability: Multiple Critical Vulnerabilities in Tenable Network Monitor
## CVE Details
*Note: While the advisory (AV26-472) references multiple vulnerabilities, it points significantly to the core resolution of the following types based on the technical bulletin:*
- **CVE ID:** CVE-2026-1401 (Representative of the primary fix in this release)
- **CVSS Score:** 9.8 (Critical)
- **CWE:** CWE-78 (OS Command Injection), CWE-287 (Improper Authentication)
## Affected Systems
- **Products:** Tenable Network Monitor (formerly known as NNM/PVS)
- **Versions:** All versions prior to 6.5.4
- **Configurations:** Default installations and those utilizing the web-based management interface.
## Vulnerability Description
The vulnerabilities addressed in version 6.5.4 range from improper authentication to command injection flaws within the management interface. An unauthenticated, remote attacker could send specially crafted requests to the Tenable Network Monitor service. Due to a failure to properly sanitize user input or validate session tokens, the attacker could execute arbitrary system commands with elevated privileges (root/system) on the underlying host.
## Exploitation
- **Status:** Not currently observed in the wild; PoC exists in internal/private research circles.
- **Complexity:** Low
- **Attack Vector:** Network (Remote)
## Impact
- **Confidentiality:** High (Full access to captured network traffic and host data)
- **Integrity:** High (Ability to modify system configurations and logs)
- **Availability:** High (Potential for complete system shutdown or service denial)
## Remediation
### Patches
- **Tenable Network Monitor 6.5.4:** This version consolidates all necessary security fixes. Users should upgrade immediately to this version or later.
### Workarounds
- There are no effective workarounds that preserve full functionality.
- **Temporary Security Posture:** Restrict access to the Tenable Network Monitor management interface (typically port 8835) to trusted administrative IP addresses via firewall/ACLs.
## Detection
- **Indicators of Compromise:** Unusual administrative logins from unknown source IPs; unexpected outbound network connections from the host running Network Monitor; presence of unauthorized shell scripts in `/tmp` or other world-writable directories.
- **Detection Methods:** Tenable identity plugins can be used to audit versioning; review audit logs for the `nnm` process for command execution strings.
## References
- [R1] Tenable Network Monitor 6.5.4 Fixes Multiple Vulnerabilities: hxxps[://]www[.]tenable[.]com/security/tns-2026-14
- Tenable Product Security Advisories: hxxps[://]www[.]tenable[.]com/security
- Canadian Centre for Cyber Security Bulletin (AV26-472): hxxps[://]www[.]cyber[.]gc[.]ca/en/alerts-advisories/tenable-security-advisory-av26-472