# CVE-2026-5720: miniupnpd: miniupnpd contains an integer underflow vulnerability in SOAPAction header parsing that allows remote attackers to ca...

CVE-2026-5720 is fixed in 5 products on 1 platform, first by miniupnpd 2.0.20171212-2ubuntu0.1~esm1, released April 17, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-5720
- Priority: High
- CVSS: 9.1 (Medium)
- EPSS: 0.0067
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Apr 17, 2026

## Description

miniupnpd contains an integer underflow vulnerability in SOAPAction header parsing that allows remote attackers to cause a denial of service or information disclosure by sending a malformed SOAPAction header with a single quote. Attackers can trigger an out-of-bounds memory read by exploiting improper length validation in ParseHttpHeaders(), where the parsed length underflows to a large unsigned value when passed to memchr(), causing the process to scan memory far beyond the allocated HTTP request buffer.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | miniupnpd Debian 13.5 (trixie) | 2.3.9-2+deb13u1 | [DEBIAN-CVE-2026-5720](https://patchblox.com/security/data/fix/linux/debian-cve-2026-5720.md) | May 15, 2026 |
| Linux | miniupnpd Debian 14 | 2.3.10-1 | [DEBIAN-CVE-2026-5720](https://patchblox.com/security/data/fix/linux/debian-cve-2026-5720.md) | May 15, 2026 |
| Linux | miniupnpd Fedora 43 | 2.3.10-1.fc43 | [FEDORA-2026-5F908CB040](https://patchblox.com/security/data/fix/linux/fedora-2026-5f908cb040.md) | Apr 20, 2026 |
| Linux | miniupnpd Ubuntu 18.04.6 LTS (bionic) | 2.0.20171212-2ubuntu0.1~esm1 | [miniupnpd 2.0.20171212-2ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-miniupnpd-2.0.20171212-2ubuntu0.1-esm1.md) | Apr 17, 2026 |
| Linux | miniupnpd Ubuntu 20.04 LTS (focal) | 2.1-6.1ubuntu0.1~esm1 | [miniupnpd 2.1-6.1ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-miniupnpd-2.1-6.1ubuntu0.1-esm1.md) | Apr 17, 2026 |
| Linux | miniupnpd Ubuntu 22.04.1 LTS (jammy) | 2.2.3-1ubuntu0.1~esm1 | [miniupnpd 2.2.3-1ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-miniupnpd-2.2.3-1ubuntu0.1-esm1.md) | Apr 17, 2026 |
| Linux | miniupnpd Ubuntu 24.04.5 LTS (noble) | 2.3.4-1ubuntu0.1~esm1 | [miniupnpd 2.3.4-1ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-noble-miniupnpd-2.3.4-1ubuntu0.1-esm1.md) | Apr 17, 2026 |
| Linux | miniupnpd Ubuntu 26.04.1 LTS (resolute) | 2.3.9-2ubuntu0.1~esm1 | [miniupnpd 2.3.9-2ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-miniupnpd-2.3.9-2ubuntu0.1-esm1.md) | Apr 17, 2026 |
| Linux | miniupnpd-debuginfo Fedora 43 | 2.3.10-1.fc43 | [FEDORA-2026-5F908CB040](https://patchblox.com/security/data/fix/linux/fedora-2026-5f908cb040.md) | Apr 20, 2026 |
| Linux | miniupnpd-debugsource Fedora 43 | 2.3.10-1.fc43 | [FEDORA-2026-5F908CB040](https://patchblox.com/security/data/fix/linux/fedora-2026-5f908cb040.md) | Apr 20, 2026 |
| Linux | miniupnpd-iptables Ubuntu 22.04.1 LTS (jammy) | 2.2.3-1ubuntu0.1~esm1 | [miniupnpd-iptables 2.2.3-1ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-miniupnpd-iptables-2.2.3-1ubuntu0.1-esm1.md) | Apr 17, 2026 |
| Linux | miniupnpd-iptables Ubuntu 24.04.5 LTS (noble) | 2.3.4-1ubuntu0.1~esm1 | [miniupnpd-iptables 2.3.4-1ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-noble-miniupnpd-iptables-2.3.4-1ubuntu0.1-esm1.md) | Apr 17, 2026 |
| Linux | miniupnpd-iptables Ubuntu 26.04.1 LTS (resolute) | 2.3.9-2ubuntu0.1~esm1 | [miniupnpd-iptables 2.3.9-2ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-miniupnpd-iptables-2.3.9-2ubuntu0.1-esm1.md) | Apr 17, 2026 |
| Linux | miniupnpd-nftables Ubuntu 22.04.1 LTS (jammy) | 2.2.3-1ubuntu0.1~esm1 | [miniupnpd-nftables 2.2.3-1ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-miniupnpd-nftables-2.2.3-1ubuntu0.1-esm1.md) | Apr 17, 2026 |
| Linux | miniupnpd-nftables Ubuntu 24.04.5 LTS (noble) | 2.3.4-1ubuntu0.1~esm1 | [miniupnpd-nftables 2.3.4-1ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-noble-miniupnpd-nftables-2.3.4-1ubuntu0.1-esm1.md) | Apr 17, 2026 |
| Linux | miniupnpd-nftables Ubuntu 26.04.1 LTS (resolute) | 2.3.9-2ubuntu0.1~esm1 | [miniupnpd-nftables 2.3.9-2ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-miniupnpd-nftables-2.3.9-2ubuntu0.1-esm1.md) | Apr 17, 2026 |

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Data as of 2026-11-08T13:06:02Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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