CVE-2026-5720

Critical

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.

SeverityCritical

CVSS9.1

Exploit probability—

ProductMiniupnp Project Miniupnpd

PublishedApr 17, 2026

First seenApr 17, 2026

Weakness typeCWE-191CWE-191 CWE-125Out-of-bounds read

How to fix

Update

miniupnp_project miniupnpd2.3.10 or later

Patches

github.com/miniupnp/miniupnp/commit/f56bd09b2f2650126b832c5f30a65a09e28167fa

Affected products

Product	Affected versions	Fixed in
miniupnp_project miniupnpd	v < 2.3.10	2.3.10

Check your version

Choose the product and enter the version you run to see whether it falls in the affected range.

In the Intelligence 360 plan

Attack Surface Management

See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.