No exploitation reported

CVE-2016-6559

No exploitation reported by the sources we read.

Published2018-07-13
WeaknessCWE-119 · CWE-120

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

Improper bounds checking of the obuf variable in the link_ntoa() function in linkaddr.c of the BSD libc library may allow an attacker to read or write from memory. The full impact and severity depends on the method of exploit and how the library is used by applications. According to analysis by FreeBSD developers, it is very unlikely that applications exist that utilize link_ntoa() in an exploitable manner, and the CERT/CC is not aware of any proof of concept. A blog post describes the functionality of link_ntoa() and points out that none of the base utilities use this function in an exploitable manner. For more information, please see FreeBSD Security Advisory SA-16:37.

Timeline

dates in UTC

2018-07-1320:29CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2016-6559?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2016-6559?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Freebsd

Branch	Affected	Fixed in	Source
9.3	= 9.3	no fix published	NVD
10.1	= 10.1	no fix published	NVD
10.2	= 10.2	no fix published	NVD
10.3	= 10.3	no fix published	NVD
11.0	= 11.0	no fix published	NVD

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Advisories and patches

www.freebsd.orgVendor Advisory

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

NVDCVSS 3.09.8read 2026-10-23
NVDCVSS 2.07.5read 2026-10-23
CNAweakness (CWE)CWE-120read 2026-10-23
NVDweakness (CWE)CWE-119read 2026-10-23
FIRST EPSSEPSS score3.7 %2026-10-23

Technical details

CVSS v3 Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published: 2018-07-13
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2016-6559?

Is CVE-2016-6559 actively exploited?

Active exploitation of CVE-2016-6559 has not been confirmed. Its EPSS score was 3.7% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2016-6559?

CVE-2016-6559 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Hear about the next vulnerability in your software

Surveillance reads the versions in your stack — a domain, a lockfile or a list — checks each CVE against the ranges its sources publish, and alerts you when one you run is exploited or enters CISA KEV. A version it cannot read stays « version not verified ».

Get alerts for this product CISA KEV additions, October 2026 Search CVEs

No credit card required · No monthly cap on website lookups · 250 API requests/month

Go further

Following what attackers exploit right now? The CISA KEV additions of the month, with their patch deadlines.
Running this software? Vulnerability monitoring alerts you to new vulnerabilities in your products.

Related vulnerabilities

Same product first, then the same vendor advisory and the same publication week.

Back to CVE Database