What’s Vulnerable › Vulnerabilities

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

• Severity: critical (CVSS 9.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.7% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-04-17 · updated 2026-10-26
• Weakness: CWE-125

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.

Affected products

• miniupnp project miniupnpd: before 2.3.10 — fixed in 2.3.10

How to fix

Upgrade to a fixed version: miniupnp project miniupnpd 2.3.10. Check the vendor advisory for mitigations.

References

• https://github.com/miniupnp/miniupnp/
• https://github.com/miniupnp/miniupnp/commit/f56bd09b2f2650126b832c5f30a65a09e28167fa
• https://www.vulncheck.com/advisories/miniupnpd-integer-underflow-soapaction-header-parsing

Get alerted when CVE-2026-5720 or the next vulnerability affects your stack