CVE-2026-5720

Name	CVE-2026-5720
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.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
Debian Bugs	1134334

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
miniupnpd (PTS)	bullseye	2.2.1-1	vulnerable
	bookworm	2.3.1-1	vulnerable
	trixie	2.3.9-2	vulnerable
	forky, sid	2.3.10-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
miniupnpd	source	(unstable)	2.3.10-1			1134334

Notes

[trixie] - miniupnpd <no-dsa> (Minor issue)
[bookworm] - miniupnpd <no-dsa> (Minor issue)
[bullseye] - miniupnpd <postponed> (Minor issue; DoS)
Fixed by: https://github.com/miniupnp/miniupnp/commit/f56bd09b2f2650126b832c5f30a65a09e28167fa (miniupnpd_2_3_10)