CVE-2026-76761: cc-connect RCE Vulnerability

CVE-2026-76761 Overview

CVE-2026-76761 is an operating system command injection vulnerability in the chenhg5 cc-connect project through version 1.4.1. The flaw resides in the shellExecCommand function within core/engine.go, which is part of the Management API component. Attackers can manipulate the exec argument to inject arbitrary operating system commands. The vulnerability is remotely exploitable without authentication or user interaction. Public exploit details are available, increasing the likelihood of opportunistic use. The upstream GitHub issue tracking the report was closed automatically due to inactivity, and no vendor patch is currently referenced.

Critical Impact
Unauthenticated remote attackers can execute arbitrary operating system commands on hosts running vulnerable cc-connect instances by supplying crafted input to the exec argument of the shellExecCommand function.

Affected Products

chenhg5 cc-connect versions up to and including 1.4.1
core/engine.go Management API component
Deployments exposing the cc-connect Management API to untrusted networks

Discovery Timeline

2026-08-19 - CVE-2026-76761 published to the National Vulnerability Database
2026-08-20 - Last updated in NVD database

Technical Details for CVE-2026-76761

Vulnerability Analysis

The vulnerability is classified as [CWE-77] Improper Neutralization of Special Elements used in a Command. The shellExecCommand function in core/engine.go accepts user-controlled input through the exec argument and passes it to a shell interpreter without adequate sanitization or argument separation. Because the Management API exposes this function over the network and does not require authentication, any reachable attacker can inject shell metacharacters or additional commands. Successful exploitation grants command execution under the privileges of the cc-connect process, which frequently runs with broad access to the host and connected systems.

Root Cause

The root cause is unsafe concatenation of attacker-controlled data into a shell command string. When the exec argument is passed to shellExecCommand, the function invokes a system shell that interprets metacharacters such as ;, &&, |, and backticks. This design pattern allows the shell to treat injected input as new commands rather than literal arguments. Using parameterized process invocation with argument arrays instead of shell strings would eliminate the injection surface.

Attack Vector

Exploitation occurs over the network against the cc-connect Management API. An attacker sends a crafted request that sets the exec parameter to a payload combining a legitimate command with shell separators followed by attacker-chosen commands. The Management API forwards the value to shellExecCommand, which executes the composite string. No prior authentication or user interaction is required, which enables scripted mass exploitation against exposed instances. The vulnerability manifests in the argument-handling logic of the Management API; refer to the VulDB Vulnerability Record and the GitHub Issue Tracker for additional technical context.

Detection Methods for CVE-2026-76761

Indicators of Compromise

Unexpected child processes spawned by the cc-connect binary, particularly shells such as sh, bash, or utilities like curl, wget, and nc.
HTTP requests to the Management API containing shell metacharacters (;, |, &&, backticks) in the exec parameter.
Outbound network connections from the cc-connect host to unfamiliar IP addresses or newly registered domains.
New cron entries, systemd units, or SSH authorized keys created after Management API activity.

Detection Strategies

Alert on process-lineage anomalies where cc-connect spawns interactive shells or scripting interpreters.
Inspect Management API access logs for parameter values that contain shell control characters or URL-encoded equivalents.
Correlate Management API request timestamps with the creation of persistence artifacts on the host.

Monitoring Recommendations

Forward cc-connect application, shell, and audit logs to a centralized analytics platform for retention and correlation.
Baseline normal Management API usage patterns and alert on deviations in source IP, request volume, and parameter content.
Monitor egress traffic from systems running cc-connect for reverse shell indicators and command-and-control patterns.

How to Mitigate CVE-2026-76761

Immediate Actions Required

Restrict network exposure of the cc-connect Management API to trusted management networks only, using firewall or security-group rules.
Place an authenticating reverse proxy in front of the Management API to block unauthenticated requests.
Audit all recent Management API traffic for suspicious exec parameter values and investigate any matches.
Run the cc-connect process under a low-privilege account to reduce impact if exploitation succeeds.

Patch Information

At the time of publication, no vendor patch is referenced in the NVD entry and the upstream GitHub Issue Tracker was closed automatically due to inactivity. Operators should monitor the GitHub Project Repository for updates and consider replacing or forking the project to apply a fix that switches shellExecCommand to argument-array process invocation without shell interpretation.

Workarounds

Disable the Management API endpoint that invokes shellExecCommand if it is not required for operations.
Apply strict input validation at a reverse proxy or web application firewall to reject requests containing shell metacharacters in the exec parameter.
Enforce network segmentation so that only administrative hosts can reach the cc-connect service.
Deploy host-based controls that block the cc-connect process from spawning shell interpreters.

bash

# Example iptables rule restricting Management API access to a trusted management subnet
iptables -A INPUT -p tcp --dport 8080 -s 10.10.0.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 8080 -j DROP