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.

References

• https://github.com/miniupnp/miniupnp/
• https://github.com/miniupnp/miniupnp/commit/a0ee71e9fa66b60052bb3d2cf84380b79db3f8c8
• https://www.vulncheck.com/advisories/miniupnpd-integer-underflow-soapaction-header-parsing