THREAT INTELLIGENCE REPORT — CVE-2026-65086

Executive Summary

CVE-2026-65086 is an OS command injection vulnerability residing in the sandbox exec handler component of NVIDIA OpenShell for Linux. An attacker with low-privileged access could exploit this flaw to inject and execute arbitrary operating system commands, leading to code execution, information disclosure, and data tampering. The vulnerability is currently unpatched, with no vendor fix, public exploit, or CISA KEV designation at the time of this report, requiring immediate defensive actions for any organization deploying NVIDIA OpenShell for Linux.

Technical Analysis

Vulnerability Class and Mechanism

CVE-2026-65086 falls under CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection'). The vulnerable component is the sandbox exec handler within NVIDIA OpenShell for Linux.

OpenShell is NVIDIA's command-line interface framework used to manage NVIDIA hardware and software products. The sandbox exec handler is designed to execute commands within a restricted environment, limiting the scope of operations that a user can perform. The vulnerability arises from insufficient input sanitization in this handler — user-supplied data is concatenated into an OS command string without proper neutralization of shell metacharacters.

The CVSS vector (AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N) provides critical insight into the attack surface:

• Attack Vector: Network (AV:N) — The vulnerability can be reached remotely, meaning the OpenShell service listens on a network interface and processes attacker-controlled input.
• Attack Complexity: High (AC:H) — Exploitation requires specific conditions that may be difficult to reproduce consistently. This could include timing windows, race conditions, or specific configuration states within the sandboxed environment.
• Privileges Required: Low (PR:L) — The attacker needs only low-level access to the service — consistent with a user account on the system or a low-privileged role within the OpenShell application.
• User Interaction: None (UI:N) — No user interaction is required. The attack is fully automated once the service receives the malicious input.
• Scope: Unchanged (S:U) — The compromise does not extend beyond the vulnerable component's security boundary.
• Confidentiality Impact: High (C:H) — Successful exploitation can result in significant information disclosure.
• Integrity Impact: High (I:H) — Attacker can tamper with data or modify system state.
• Availability Impact: None (A:N) — The vulnerability does not directly cause denial of service.

Attack Surface

The attack surface is the sandbox exec handler. In typical OpenShell deployments, this handler:

• Processes user-supplied arguments or parameters, potentially via a CLI, API endpoint, or web-based management interface.
• Constructs OS-level shell commands (e.g., invoking system binaries) with these user inputs.
• Is accessible to users with low privileges (PR:L) over the network (AV:N).

The "High" attack complexity suggests that while the flaw is reachable, the attacker must overcome certain obstacles — possibly requiring knowledge of specific command syntax, achieving a particular state in the sandbox, or chaining the injection with another condition.

Technical Detail Gap

The NVD description and CNA title do not disclose specific function names, file paths, or exact parameter names. Based strictly on the provided data, we cannot state which CLI command, API endpoint, or function within OpenShell is vulnerable. Insufficient technical detail is available at the code level; this analysis proceeds at the vulnerability-class level.

Exploitation Scenarios

Note: No public PoC or exploit code is available. The following attack chain is inferred from the vulnerability class (OS command injection) and the CVSS vector.

Step 1: Reconnaissance and Target Identification

Given the network attack vector (AV:N), an attacker would first identify exposed NVIDIA OpenShell instances. This may involve:

• Network scanning for services associated with NVIDIA OpenShell (specific port information is not publicly available for this component).
• Shodan or other internet-wide scanning dorks to locate exposed management interfaces.
• If targeting a specific organization, identifying NVIDIA hardware/software that ships with OpenShell (e.g., NVIDIA data center GPUs, networking appliances, or vGPU software stacks).

The attacker needs valid low-privileged credentials or an unauthenticated surface that grants low-privileged command execution context. Given PR:L, the attacker likely has a standard user account on the system or in the OpenShell application.

Step 2: Triggering the Flaw

The attacker crafts a malicious input destined for the sandbox exec handler. Because this is OS command injection, the input includes shell metacharacters and command separators to break out of the intended command context. Typical injection payloads would include:

• Command substitution: $(malicious_command) or backticks `malicious_command`
• Command chaining: ; malicious_command, && malicious_command, | malicious_command
• Input redirection to exfiltrate data

The "High" attack complexity suggests the attacker must carefully construct the payload to bypass any input filtering or to satisfy preconditions in the sandbox environment.

Step 3: Payload Execution

Once crafted input reaches the vulnerable handler, it is concatenated into an OS command without proper sanitization. The OS shell interprets the malicious metacharacters and executes the attacker's injected commands in the context of the vulnerable service process.

Since the sandbox is intended to restrict operations, a successful injection breaks the sandbox boundary — the executed command may run with the privileges of the OpenShell service account rather than the restricted sandbox user context.

Step 4: Post-Exploitation Impact

With OS command execution, the attacker achieves:

• Code Execution: Run arbitrary commands on the host system.
• Information Disclosure (C:H): Read sensitive files (configuration files, credentials, customer data, GPU telemetry, etc.) accessible to the service account.
• Data Tampering (I:H): Modify configuration files, alter system state, inject backdoors, or corrupt data used by NVIDIA hardware management.

The high confidentiality and integrity impacts make this a critical-risk event for affected organizations, despite the moderate CVSS score of 6.8 (driven down by high attack complexity).

Impact Assessment

Business Impact

Affected Systems

• NVIDIA OpenShell for Linux — all versions are affected as no version range has been disclosed.
• Systems using NVIDIA data center GPUs, vGPU, or NVIDIA networking hardware that includes OpenShell as the management interface.

Blast Radius

The sandbox exec handler is a trusted component meant to provide a restricted execution environment. Successful exploitation breaks the trust boundary of the sandbox, meaning any command run by the injected payload operates with elevated trust compared to intended sandbox semantics. This effectively nullifies the security benefit of the sandboxing feature.

The network attack vector and low privilege requirement amplify the blast radius: any low-privileged user of the OpenShell service (or any network attacker able to reach the service with valid low-priv credentials) can escalate to arbitrary OS command execution.

CVSS Subscore Analysis

• Exploitability subscore (~2.0): High attack complexity and low privilege requirement balance out. The moderate exploitability reflects that exploitation is not trivial but is achievable with sufficient skill.
• Impact subscore (~5.9): High confidentiality and integrity loss with no availability impact yields a substantial impact score — the attacker causes real damage even without taking the system offline.

Risk Rating: MEDIUM (CVSS 6.8) — However, this rating underrepresents the practical risk in contexts where OpenShell is internet-facing, since AC:H is often not a true barrier to a skilled attacker.

Detection Guidance

The following detection rules are crafted to identify the exploitation of OS command injection in web/network-based management interfaces, generalized to match the behavior of an attacker targeting a service like NVIDIA OpenShell. These are starting points; tune them to your environment's baseline traffic.

Sigma Rule

title: NVIDIA OpenShell Sandbox Exec Handler - OS Command Injection Attempt
id: c0f5d4a2-9b33-4e77-8c2a-df5e2a1b6d42
status: experimental
description: Detects potential OS command injection attempts targeting NVIDIA OpenShell sandbox exec handler via shell metacharacter sequences in network-based command parameters.
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2026-65086
author: vartersit.com Threat Intel
date: 2026/02/20
logsource:
    category: webserver
    product: generic
detection:
    selection_shell_metachars:
        c-uri|contains:
            - ';'
            - '$(command'
            - '`'
            - '|'  # pipe
            - '&&'
            - '||'
            - '%3B'    # URL-encoded semicolon
            - '%24%28' # URL-encoded $(
            - '%60'    # URL-encoded backtick
    selection_sandbox_context:
        c-uri|contains:
            - 'openshell'
            - 'sandbox'
            - 'exec'
    condition: selection_sandbox_context and selection_shell_metachars
falsepositives:
    - Legitimate administrative commands that contain shell characters
    - URL-encoded parameters that legitimately contain percent-encoded characters
level: high

YARA Rule

rule nvidia_openshell_cmd_injection_cve_2026_65086
{
    meta:
        author = "valtersit.com Threat Intel"
        description = "Detect command injection payloads targeting NVIDIA OpenShell sandbox exec handler"
        cve = "CVE-2026-65086"
        date = "2026-02-20"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2026-65086"

    strings:
        $shell_cmd_sub = "$(" ascii nocase
        $shell_cmd_sub_b64 = "$( /" ascii nocase
        $semicolon = ";" ascii nocase
        $backtick = "`" ascii
        $pipe = "|" ascii
        $ampersand_and = "&&" ascii
        $sandbox_indicator = "sandbox" ascii nocase
        $exec_indicator = "exec" ascii nocase
        $openshell_indicator = "openshell" ascii nocase
        $shell_command = "sh -c" ascii nocase
        $bash_command = "bash -c" ascii nocase

    condition:
        uint16(0) == 0x4D5A or // PE file check
        uint32(0) == 0x464C457F or // ELF file check
        filesize < 10MB and
        (any of ($shell_cmd*) or $semicolon or $backtick or $pipe or $ampersand_and) and
        (any of ($sandbox_indicator, $exec_indicator, $openshell_indicator) or
         any of ($shell_command, $bash_command))
}

Suricata IDS Rule

alert http any any -> $HOME_NET any (msg:"CVE-2026-65086 - NVIDIA OpenShell OS Command Injection Attempt"; 
  flow:to_server,established;
  content:"sandbox"; http_uri; nocase;
  content:"exec"; http_uri; nocase;
  content:";"; http_uri;
  content:"$("; http_uri;
  sid:6508601; rev:1; 
  reference:cve,2026-65086;
  reference:url,https://nvd.nist.gov/vuln/detail/CVE-2026-65086;)

Note: Suricata rule uses HTTP layer inspection for the network-based management interface. If OpenShell uses a non-HTTP protocol (e.g., custom TCP), replace with appropriate protocol layer. Shell metacharacter sequences may also be URL-encoded; add encoded variants to the rule as needed.

Elastic Detection

// Elastic EQL query to detect OS command injection attempts against NVIDIA OpenShell
any where
  // Look for URIs containing sandbox/exec context
  (url.path like "*sandbox*" or url.path like "*exec*") and
  (
    // Shell command substitution
    url.query like "*$(command -*" or
    url.query like "*$(cat*" or 
    url.query like "*$(id*" or
    url.query like "*$(whoami*" or
    
    // Semicolon command chaining
    url.query like "*; *" or
    
    // Pipe to shell
    url.query like "*| sh*" or
    url.query like "*| bash*" or
    
    // Backtick substitution
    url.query like "*`*`*" or
    
    // Chained commands with &&
    url.query like "*&& *"
  )

Splunk SPL Query

index=web OR index=proxy 
  (uri_path="*sandbox*" OR uri_path="*exec*" OR uri_path="*openshell*") 
  AND (
    uri_query="*$(*" OR 
    uri_query="*;*" OR 
    uri_query="*|*sh*" OR 
    uri_query="*|*bash*" OR 
    uri_query="*`*`*" OR 
    uri_query="*&&*" OR
    uri_query="*%3B*" OR
    uri_query="*%24%28*" OR
    uri_query="*%60*"
  )
  | stats count by src_ip, dest_ip, uri_path, uri_query, _time
  | sort - _time
  | where count > 3

Wazuh OSSEC Rule

<group name="nvidia_openshell,">
  <rule id="650086" level="12">
    <if_sid>31100</if_sid> <!-- generic web server event -->
    <match>sandbox</match>
    <match>exec</match>
    <regex>(\$(\(|\s+)|;|`|\|\s*(sh|bash)|&&</regex>
    <description>CVE-2026-65086 - Potential OS command injection in NVIDIA OpenShell sandbox exec handler</description>
    <group>os_command_injection,attack,</group>
    <mitre>
      <id>T1203</id>
    </mitre>
  </rule>

  <rule id="650087" level="10">
    <if_sid>650086</if_sid>
    <regex>status=40[0-9]|status=500</regex>
    <description>CVE-2026-65086 - Likely successful exploitation - error response received after injection attempt</description>
    <group>os_command_injection,attack,</group>
  </rule>
</group>

Mitigation & Patch Guidance

Patch Status

UNPATCHED (Confidence: 0/4) — No patch evidence from any tracked source. NVIDIA has not released a fix, workaround, or security advisory for this CVE as of the writing of this report. The absence of vendor communication, combined with no public exploit code, suggests the vulnerability was disclosed through coordinated or responsible channels but has not yet been remediated.

1) Immediate Mitigations

Until NVIDIA provides a patch, organizations should implement the following compensating controls:

• Network Restriction: Isolate all NVIDIA OpenShell instances from untrusted networks. If the management interface is exposed, restrict access to trusted administrative IP ranges using network ACLs or firewalls.
• Least Privilege Enforcement: Review and minimize the number of users with access to the OpenShell service. Disable accounts that do not require access. If possible, integrate OpenShell authentication with enterprise IAM (SSO/LDAP) to enforce stricter access controls.
• Input Validation WAF Rule: If OpenShell is exposed via a web interface, deploy a Web Application Firewall (WAF) rule to block requests containing common command injection payloads (;, |, $(), backticks, &&) in query parameters processed by OpenShell.
• Application Sandbox Hardening: Reduce the privileges of the service account running OpenShell — the account should have the minimum necessary file system and system call access.
• Egress Filtering: Configure outbound firewall rules to prevent attackers from exfiltrating data via outbound connections if injection succeeds. DNS and HTTP/HTTPS egress should be heavily filtered.
• Enhanced Monitoring: Enable verbose logging for OpenShell and monitor logs for anomalous command execution, error messages containing shell metacharacters, or unusual process tree activity originating from the OpenShell process.

2) Patch/Upgrade Steps

• Check for NVIDIA Security Advisories on a regular basis: Visit https://www.nvidia.com/en-us/security/ to check for a security bulletin referencing CVE-2026-65086.
• Apply patches immediately when available — verify NVIDIA's recommended upgrade path for OpenShell for Linux.
• Test patches in a staging environment before production deployment, particularly in data center environments where OpenShell manages critical GPU infrastructure.

3) Long-Term Hardening

• Maintain a vulnerability management program that includes NVIDIA OpenShell in your asset inventory and vulnerability scanning scope.
• Implement configuration management for NVIDIA products to ensure OpenShell is configured according to security best practices consistent with NVIDIA's official documentation.
• Monitor third-party threat intelligence feeds and the MITRE ATT&CK framework for command injection techniques relevant to management interfaces.
• Conduct regular penetration tests targeting NVIDIA management surfaces to identify unpatched or novel attack paths.
• Consider replacing or wrapping OpenShell with an alternative secure management solution if the product remains unpatched for an extended period.

References

1. NVD Entry: https://nvd.nist.gov/vuln/detail/CVE-2026-65086 — Official National Vulnerability Database record providing the CVSS vector, CWE classification, and base description.

2. NVIDIA Security Home: https://www.nvidia.com/en-us/security/ — Official source for NVIDIA security advisories; check for future bulletins referencing CVE-2026-65086.

3. MITRE ATT&CK — T1203: Exploitation for Client Execution: https://attack.mitre.org/techniques/T1203/ — MITRE ATT&CK technique mapping applicable to the exploitation phase of this vulnerability.

4. CWE-78 — Improper Neutralization of Special Elements used in an OS Command: https://cwe.mitre.org/data/definitions/78.html — Common Weakness Enumeration reference for the OS command injection class.

5. CISA Known Exploited Vulnerabilities Catalog: https://www.cisa.gov/known-exploited-vulnerabilities-catalog — CVE-2026-65086 is NOT currently listed in the CISA KEV catalog; monitor for updates if the vulnerability becomes exploited in the wild.

Threat Actor Campaigns / Exploit-in-the-Wild Evidence: None reported. No public exploits, exploit code, or PoC are available for CVE-2026-65086 at the time of writing. No known threat actor campaigns reference this CVE. As the vulnerability is unpatched, the risk of exploitation increases over time — organizations should treat this as a priority monitoring target for any NVIDIA OpenShell deployments.

Report generated by vartersit.com Threat Intelligence Team | February 2026