7.1
HIGH CVSS 4.0
CVE-2026-5720
miniupnpd Integer Underflow SOAPAction Header Parsing
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.

INFO

Published Date :

April 17, 2026, 10:16 p.m.

Last Modified :

April 17, 2026, 10:16 p.m.

Remotely Exploit :

No
Affected Products

The following products are affected by CVE-2026-5720 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 4.0 HIGH 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 4.0 HIGH [email protected]
Solution
Update miniupnpd to fix integer underflow in SOAPAction header parsing.
  • Update miniupnpd to the latest version.
  • Apply vendor-provided patches for miniupnpd.
  • Validate SOAPAction header parsing logic.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-5720.

URL Resource
https://github.com/miniupnp/miniupnp/
https://github.com/miniupnp/miniupnp/commit/a0ee71e9fa66b60052bb3d2cf84380b79db3f8c8
https://www.vulncheck.com/advisories/miniupnpd-integer-underflow-soapaction-header-parsing
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-5720 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-5720 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-5720 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-5720 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Apr. 17, 2026

    Action Type Old Value New Value
    Added 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.
    Added CVSS V4.0 AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CWE CWE-125
    Added CWE CWE-191
    Added Reference https://github.com/miniupnp/miniupnp/
    Added Reference https://github.com/miniupnp/miniupnp/commit/a0ee71e9fa66b60052bb3d2cf84380b79db3f8c8
    Added Reference https://www.vulncheck.com/advisories/miniupnpd-integer-underflow-soapaction-header-parsing
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.