Buffer overflow in D-Link Dir-816

CVE-2026-4181

A security flaw has been discovered in D-Link DIR-816 1.10CNB05. This affects an unknown function of the file /goform/form2RepeaterStep2.cgi of the component goahead. The manipulation of the argument key1/key2/key3/key4/pskValue results in stack-based buffer overflow. The attack may be launched remotely. The exploit has been released to the public and may be used for attacks. This vulnerability only affects products that are no longer supported by the maintainer.

Vulnerability class: Buffer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.019 (78.6th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 79th percentile — 78.6% 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-2026-4181: rose from 0.012 to 0.019.

EPSS over last 30 days · oldest: 0.012 · newest: 0.019 · change: +0.007

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-4181?
CVE-2026-4181 is a critical-severity vulnerability in D-Link Dir-816, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 9.8/10. Published 2026-03-16.
How severe is CVE-2026-4181?
Critical severity. CVSS v3 base score is 9.8 out of 10.