CVE-2026-86151 Overview
CVE-2026-86151 is an operating system command injection vulnerability affecting Tenda CP3 firmware version 27.5.57.101. The flaw resides in the sub_2F77E8 function within Apis/system.c, part of the device's Network Configuration Management component. Attackers can inject arbitrary shell commands by manipulating input processed by this function. The issue is classified under CWE-77: Improper Neutralization of Special Elements used in a Command and can be triggered remotely over the network.
Critical Impact
Successful exploitation grants command execution on the affected Tenda CP3 device, compromising the confidentiality, integrity, and availability of the network camera and any traffic it handles.
Affected Products
- Tenda CP3 firmware version 27.5.57.101
- Component: Network Configuration Management (Apis/system.c)
- Vulnerable function: sub_2F77E8
Discovery Timeline
- 2026-09-06 - CVE-2026-86151 published to NVD
- 2026-09-08 - Last updated in NVD database
Technical Details for CVE-2026-86151
Vulnerability Analysis
The vulnerability exists in sub_2F77E8, a handler compiled into the Tenda CP3 firmware from Apis/system.c. This function processes network configuration parameters supplied through the device management interface. Attacker-controlled input flows into a shell command construction path without adequate neutralization of command separators or metacharacters. When the constructed string reaches a system-level execution primitive, injected commands run under the privileges of the calling service on the embedded Linux device.
The attack surface is reachable across the network. Exploitation requires high privileges according to the CVSS 4.0 vector, meaning an authenticated management context is expected. Impact spans both the vulnerable component and adjacent subsystems, including downstream network components the camera can reach.
Root Cause
The root cause is improper neutralization of special elements passed into a shell command string [CWE-77]. The sub_2F77E8 function concatenates user-controlled parameters directly into a command line invoked through a system shell. Because shell metacharacters such as ;, |, `, and $() are not filtered or escaped, attackers append arbitrary commands to the intended operation.
Attack Vector
Attackers reach the vulnerability through the CP3 management network interface exposed by the Network Configuration Management component. After acquiring the required privileges, an attacker submits a crafted configuration request whose parameters embed shell metacharacters. The sub_2F77E8 function passes the tainted string to a shell, causing the injected commands to execute on the embedded device.
No verified proof-of-concept code is published at this time. Technical details are tracked in the VulDB CVE-2026-86151 entry and the associated VulDB Vulnerability #399274.
Detection Methods for CVE-2026-86151
Indicators of Compromise
- Unexpected child processes spawned by the CP3 network configuration service, such as sh, busybox, wget, or curl invocations initiated from configuration workflows.
- Configuration API requests containing shell metacharacters (;, &, |, `, $()) in parameters processed by the Network Configuration Management component.
- Outbound connections from Tenda CP3 devices to unfamiliar hosts, particularly on ports associated with reverse shells or payload staging.
Detection Strategies
- Inspect HTTP request bodies and query strings sent to CP3 management endpoints for command-injection payload patterns.
- Baseline normal process activity on the device and alert on new executables, shell invocations, or interpreters launched by system management binaries.
- Correlate authentication events against the CP3 admin interface with subsequent configuration changes to identify anomalous administrative activity.
Monitoring Recommendations
- Forward network telemetry from CP3 management VLANs into a centralized analytics platform for anomaly detection.
- Monitor DNS and egress traffic from IoT segments for beaconing, downloader activity, or connections to known malicious infrastructure.
- Track firmware version inventory across deployed CP3 devices to identify hosts still running the vulnerable 27.5.57.101 build.
How to Mitigate CVE-2026-86151
Immediate Actions Required
- Restrict management access to Tenda CP3 devices to a dedicated administrative VLAN, and block the management interface from untrusted networks.
- Rotate administrative credentials and enforce strong, unique passwords to reduce the chance an attacker satisfies the high-privilege requirement.
- Audit CP3 devices for signs of prior exploitation, including unauthorized configuration changes and unexpected outbound connections.
Patch Information
At the time of publication, no vendor patch is referenced in the CVE record. Consult the Tenda official website for firmware advisories and updated releases addressing CVE-2026-86151.
Workarounds
- Place CP3 cameras behind a firewall that blocks inbound access to the web management interface from all networks except a hardened jump host.
- Disable remote administration features on the device where operational requirements permit local-only management.
- Segment IoT devices from production and user networks so that a compromised CP3 cannot pivot into higher-value assets.
# Example firewall rule restricting CP3 management access to a trusted subnet
iptables -A FORWARD -s 10.20.30.0/24 -d <CP3_IP> -p tcp --dport 80 -j ACCEPT
iptables -A FORWARD -d <CP3_IP> -p tcp --dport 80 -j DROP
iptables -A FORWARD -d <CP3_IP> -p tcp --dport 443 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.