miniupnp project miniupnpd up to 2.3.9 HTTP Request ParseHttpHeaders integer underflow

Summaryinfo

A vulnerability, which was classified as critical, was found in miniupnp project miniupnpd up to 2.3.9. This impacts the function ParseHttpHeaders of the component HTTP Request Handler. Such manipulation leads to integer underflow. This vulnerability is documented as CVE-2026-5720. The attack requires being on the local network. There is not any exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in miniupnp project miniupnpd up to 2.3.9. It has been rated as critical. Affected by this issue is the function ParseHttpHeaders of the component HTTP Request Handler. The manipulation with an unknown input leads to a integer underflow vulnerability. Using CWE to declare the problem leads to CWE-191. The product subtracts one value from another, such that the result is less than the minimum allowable integer value, which produces a value that is not equal to the correct result. Impacted is confidentiality, integrity, and availability. CVE summarizes:

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.

The weakness was released by Kazuma Matsumoto. The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-5720 since 04/06/2026. The exploitation is known to be easy. The attack can only be initiated within the local network. No form of authentication is required for exploitation. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 307450 (Linux Distros Unpatched Vulnerability : CVE-2026-5720), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 2.3.10 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (307450) and EUVD (EUVD-2026-23565). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

• Project Management Software

Vendor

• miniupnp project

Name

• miniupnpd

Version

• 2.3.0
• 2.3.1
• 2.3.2
• 2.3.3
• 2.3.4
• 2.3.5
• 2.3.6
• 2.3.7
• 2.3.8
• 2.3.9

CPE 2.3info

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CPE 2.2info

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VulDB is the best source for vulnerability data and more expert information about this specific topic.

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