Out-of-bounds Read in Miniupnp Project Miniupnpd

CVE-2026-5720

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.

Vulnerability class: Buffer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H.

EPSS exploit prediction

EPSS: 0.011 (63.5th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 63rd percentile — 63.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-5720: held from 0.007 to 0.011.

EPSS over last 30 days · oldest: 0.007 · newest: 0.011 · change: +0.004

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-5720?
CVE-2026-5720 is a critical-severity vulnerability in Miniupnp Project Miniupnpd, classified under Out-of-bounds Read. CVSS score: 9.1/10. Published 2026-04-17.
How severe is CVE-2026-5720?
Critical severity. CVSS v3 base score is 9.1 out of 10.