TrueConf Server Remote Code Execution and Sandbox Escape Vulnerability Advisory (CVE-2026-72530)

1. Apply Official Security Patches

Immediately upgrade your TrueConf Server instance to the latest secure version recommended by the vendor.

2. Temporary Network Mitigation

If patching cannot be applied immediately, restrict access to TCP port 4307 using network firewalls or security groups.

Linux (iptables) Example:

# Allow TCP 4307 only from a trusted management IP (e.g., 192.168.1.100)
sudo iptables -A INPUT -p tcp -s 192.168.1.100 --dport 4307 -j ACCEPT
# Block all other traffic to TCP 4307
sudo iptables -A INPUT -p tcp --dport 4307 -j DROP

Windows PowerShell Example:

# Create an inbound block rule for TCP port 4307
New-NetFirewallRule -DisplayName "Block TrueConf TCP 4307" `
    -Direction Inbound `
    -LocalPort 4307 `
    -Protocol TCP `
    -Action Block

CVE-2026-72530 is a critical code injection (CWE-94) and sandbox escape vulnerability in TrueConf Server.

The vulnerability lies in the handling of network requests on TCP port 4307. An unauthenticated attacker with network access to this port can transmit a specially crafted script payload. Due to insufficient validation within the server's execution environment, the script breaks out of the isolated sandbox container and executes directly on the host operating system.

This vulnerability is actively exploited in the wild by threat actors (such as Head Mare deploying PhantomCore malware) and is listed on the CISA KEV catalog with an EPSS score of 0.94, indicating an extremely high risk of exploitation.