CVE-2026-5720 HIGH

CVE-2026-5720: miniupnpd Integer Underflow SOAPAction Header Parsing

Vendor Miniupnp Project
Product miniupnpd
Weakness CWE-191
Published April 17, 2026
Last update May 4, 2026

CVSS base score

7.1/10
Attack vector Adjacent
Attack complexity Low
Privileges required None
User interaction None
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

April 17, 2026 CVE published
May 4, 2026 Record updated