CVE-2026-2630
Product: Tenable Security Center
Vulnerability Type: OS Command Injection (CWE-78)
CVSS v3.1: 8.8 (High)
Vector: AV:N / AC:L / PR:L / UI:N / S:U / C:H / I:H / A:H
Severity: High
Attack Vector: Network (Web UI / API)
Privileges Required: Low (Authenticated user)
User Interaction: None
Exploitability: Low complexity once authenticated
Exploit Availability: No official exploit published by vendor; third-party research discussions observed. Risk of weaponization considered high due to vulnerability class.
Official Patch / Upgrade Link:
https://www.tenable.com/security/tns-2026-06
Overview
CVE-2026-2630 is a command injection vulnerability identified in Tenable Security Center. Insufficient neutralization of user-supplied input before it is passed to system-level commands allows authenticated users to execute arbitrary operating system commands on the underlying host.
The issue resides in backend components that invoke shell commands as part of processing certain application functions. Improper input validation enables injection of shell metacharacters, leading to execution of unintended commands with the privileges of the Security Center service account.
Because the application typically runs with elevated system privileges, successful exploitation may result in full server compromise.
Technical Details
The vulnerability is categorized under CWE-78: Improper Neutralization of Special Elements used in an OS Command.
It was identified that specific input parameters submitted through the web interface or API are concatenated into system-level command strings without strict validation or proper escaping. If malicious input is introduced, command separators or subshell expressions may be interpreted by the shell.
Common injection vectors in such scenarios include:
- Command separators (
;,&&,||) - Subshell expressions (
$()) - Backticks (
`) - Pipe characters (
|) - Redirection operators (
>,<)
When processed by the shell, these characters allow execution of additional unintended commands.
The vulnerability requires authentication; however, only low-privileged access is needed. Therefore, compromise of a standard user account or misuse of API credentials could enable exploitation.
Impact
If successfully exploited, the following impacts may occur:
- Execution of arbitrary system commands
- Retrieval of sensitive configuration files
- Modification of system configuration
- Creation of new privileged accounts
- Installation of persistence mechanisms
- Lateral movement within the network
- Disruption or deletion of data
Because Tenable Security Center often holds vulnerability scan data, credentials, and integration secrets, compromise may expose highly sensitive internal security information.
Attack Scenario
- An attacker gains valid credentials (via phishing, password reuse, brute force, or insider access).
- The attacker authenticates to the Security Center web interface or API.
- A vulnerable parameter is supplied with malicious shell characters.
- The backend constructs a system command using unsanitized input.
- The shell interprets injected characters and executes arbitrary commands.
- Persistence or data exfiltration activities may follow.
No user interaction is required beyond authentication.
MITRE ATT&CK Mapping
- T1078 – Valid Accounts
Exploitation requires authenticated access. - T1059 – Command and Scripting Interpreter
Arbitrary shell commands executed on the host. - T1105 – Ingress Tool Transfer
Additional tools may be downloaded post-exploitation. - T1547 – Boot or Logon Autostart Execution
Persistence mechanisms may be deployed. - T1041 – Exfiltration Over C2 Channel
Data may be exfiltrated over network connections.
Proof of Concept (Educational)
No official vendor PoC has been released.
From a technical perspective, command injection vulnerabilities are typically validated in controlled lab environments by supplying crafted input containing shell control characters within vulnerable parameters. Successful exploitation is generally confirmed if:
- Unexpected command output appears in application responses.
- New system processes are spawned.
- Files are created or modified without legitimate action.
Detection and Monitoring
Log Sources
Monitoring should focus on:
- Web server access logs
- Application logs from Security Center
- Linux system logs (syslog, messages)
- auditd logs
- EDR telemetry
- Process execution logs
- Authentication logs
Indicators of Exploitation
The following behaviors may indicate exploitation attempts:
- HTTP requests containing shell metacharacters in parameters.
- Unexpected invocation of
/bin/sh,/bin/bash, or similar shells by the Security Center process. - Outbound network connections initiated by the Security Center host unexpectedly.
- Creation of new cron jobs or modification of startup scripts.
- Unusual file access under
/etc,/var,/home, or application directories. - High CPU usage correlated with suspicious API calls.
Detection Queries
Splunk – Suspicious Characters in Web Requests
index=web_logs sourcetype=access_combined
| search uri_query="*;*" OR uri_query="*&&*" OR uri_query="*||*" OR uri_query="*`*"
| stats count by src_ip, uri, uri_query
Splunk – Suspicious Process Spawn
index=os_logs sourcetype=linux_secure
| search process_name="bash" OR process_name="sh"
| stats count by user, parent_process, command_line
Linux Auditd Rule
auditctl -a always,exit -F arch=b64 -S execve -F euid=<security_center_uid> -k sc_exec_monitor
ausearch -k sc_exec_monitor
EDR Hunting Query Concept
Search for:
- Parent process: Security Center service
- Child process: shell interpreter
- Command line containing metacharacters
WAF Detection Pattern
Trigger alert when:
- HTTP POST body contains command separators AND
- Request targets Security Center management endpoint
False positives must be tuned carefully.
Remediation
The vulnerability has been addressed by Tenable in patched builds of Security Center.
Immediate actions recommended:
- Upgrade to the patched version using the official advisory link above.
- Restrict administrative interface access to trusted IP ranges.
- Enforce strong password policy and multi-factor authentication.
- Rotate API keys and service credentials.
- Review logs for exploitation attempts prior to patching.
- Validate file integrity after upgrade.
Temporary mitigations such as WAF filtering may reduce exposure but should not replace patching.
Risk Considerations
Although authentication is required, risk remains high because:
- Low privilege accounts may be sufficient.
- Credential theft is common in enterprise environments.
- Command injection vulnerabilities are frequently weaponized.
- Exploitation can lead to full system takeover.
Organizations running Tenable Security Center in internet-accessible environments face elevated exposure.
Conclusion
CVE-2026-2630 represents a high-impact authenticated command injection vulnerability in Tenable Security Center. Successful exploitation allows arbitrary operating system command execution and may result in complete compromise of the affected host.
