What is CVE-2021-31718?

CVE-2021-31718 is a high-severity vulnerability in Npupnp Project, classified under Origin Validation Error. CVSS score: 8.8/10. Published 2021-04-25.

How severe is CVE-2021-31718?

High severity. CVSS v3 base score is 8.8 out of 10.

Vulnerability in Npupnp Project

CVE-2021-31718

The server in npupnp before 4.1.4 is affected by DNS rebinding in the embedded web server (including UPnP SOAP and GENA endpoints), leading to remote code execution.

Published 2021-04-25 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.010 (60.0th percentile), scored 2026-10-01.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 60th percentile — 60.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.010 · newest: 0.010 · change: 0.000

Affected products

Npupnp Project

Weakness classification (CWE)

CWE-346 — Origin Validation Error

References

framagit.org/medoc92/npupnp (Third Party Advisory)
www.lesbonscomptes.com/upmpdcli/npupnp-doc/libnpupnp.html (Third Party Advisory)
www.openwall.com/lists/oss-security/2021/04/25/2 (Mailing List, Third Party Advisory)

Frequently asked questions

What is CVE-2021-31718?: CVE-2021-31718 is a high-severity vulnerability in Npupnp Project, classified under Origin Validation Error. CVSS score: 8.8/10. Published 2021-04-25.
How severe is CVE-2021-31718?: High severity. CVSS v3 base score is 8.8 out of 10.