Ubuntu Security Notices USN-8731-1 USN-8731-1: MiniUPnPd vulnerability Publication date 7 September 2026 Overview MiniUPnPd could be made to crash or expose sensitive information if it received specially crafted network traffic. Releases 26.04 LTS 24.04 LTS 22.04 LTS 20.04 LTS 18.04 LTS 16.04 LTS Open side navigation Close side navigation Packages Details Update instructions References Packages miniupnpd - UPnP Internet Gateway Device Daemon Details It was discovered that MiniUPnPd contained an integer underflow vulnerability in SOAPAction header parsing. A remote attacker could use this issue to cause a denial of service or information disclosure by sending a malformed SOAPAction header with a single quote. It was discovered that MiniUPnPd contained an integer underflow vulnerability in SOAPAction header parsing. A remote attacker could use this issue to cause a denial of service or information disclosure by sending a malformed SOAPAction header with a single quote. Update instructions In general, a standard system update will make all the necessary changes. Learn more about how to get the fixes. The problem can be corrected by updating your system to the following package versions: Ubuntu Release Package Version 26.04 LTS resolute miniupnpd – 2.3.9-2ubuntu0.1~esm1 Ubuntu Pro Fix available with Ubuntu Pro via ESM Apps. A community fix might become publicly available in the future. miniupnpd-iptables – 2.3.9-2ubuntu0.1~esm1 Ubuntu Pro Fix available with Ubuntu Pro via ESM Apps. A community fix might become publicly available in the future. miniupnpd-nftables – 2.3.9-2ubuntu0.1~esm1 Ubuntu Pro Fix available with Ubuntu Pro via ESM Apps. A community fix might become publicly available in the future. 24.04 LTS noble miniupnpd – 2.3.4-1ubuntu0.1~esm1 Ubuntu Pro Fix available with Ubuntu Pro via ESM Apps. A community fix might become publicly available in the future. miniupnpd-iptables – 2.3.4-1ubuntu0.1~esm1 Ubuntu Pro Fix available with Ubuntu Pro via ESM Apps. A community fix might become publicly available in the future. miniupnpd-nftables – 2.3.4-1ubuntu0.1~esm1 Ubuntu Pro Fix available with Ubuntu Pro via ESM Apps. A community fix might become publicly available in the future. 22.04 LTS jammy miniupnpd – 2.2.3-1ubuntu0.1~esm1 Ubuntu Pro Fix available with Ubuntu Pro via ESM Apps. A community fix might become publicly available in the future. miniupnpd-iptables – 2.2.3-1ubuntu0.1~esm1 Ubuntu Pro Fix available with Ubuntu Pro via ESM Apps. A community fix might become publicly available in the future. miniupnpd-nftables – 2.2.3-1ubuntu0.1~esm1 Ubuntu Pro Fix available with Ubuntu Pro via ESM Apps. A community fix might become publicly available in the future. 20.04 LTS focal miniupnpd – 2.1-6.1ubuntu0.1~esm1 Ubuntu Pro Fix available with Ubuntu Pro via ESM Apps. A community fix might become publicly available in the future. 18.04 LTS bionic miniupnpd – 2.0.20171212-2ubuntu0.1~esm1 Ubuntu Pro Fix available with Ubuntu Pro via ESM Apps. A community fix might become publicly available in the future. 16.04 LTS xenial miniupnpd – 1.8.20140523-4.1+deb9u2ubuntu0.1~esm1 Reduce your security exposure Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines. Get Ubuntu Pro References CVE-2026-5720 CVE-2026-5720