No exploitation reportedFix available

CVE-2016-3947

No exploitation reported by the sources we read.

Published2016-04-07
WeaknessCWE-119

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

Heap-based buffer overflow in the Icmp6::Recv function in icmp/Icmp6.cc in the pinger utility in Squid before 3.5.16 and 4.x before 4.0.8 allows remote servers to cause a denial of service (performance degradation or transition failures) or write sensitive information to log files via an ICMPv6 packet.

Timeline

dates in UTC

2016-04-0718:59CVE publishedNVD
2026-10-2319:23EPSS crossed 10 %FIRST EPSS

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 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-2016-3947?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2016-3947?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Squid-cache squid

Branch	Affected	Fixed in	Source
3.5	≤ 3.5.15	no fix published	NVD
4.0	= 4.0.1	no fix published	NVD
4.0	= 4.0.2	no fix published	NVD
4.0	= 4.0.3	no fix published	NVD
4.0	= 4.0.4	no fix published	NVD
4.0	= 4.0.5	no fix published	NVD
4.0	= 4.0.6	no fix published	NVD
4.0	= 4.0.7	no fix published	NVD

Canonical ubuntu linux

Branch	Affected	Fixed in	Source
12.4	= 12.04	no fix published	NVD
14.4	= 14.04	no fix published	NVD
15.10	= 15.10	no fix published	NVD
16.4	= 16.04	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

Detection

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

Sources

NVDCVSS 3.08.2read 2026-10-23
NVDCVSS 2.07.5read 2026-10-23
NVDweakness (CWE)CWE-119read 2026-10-23
FIRST EPSSEPSS score14.6 %read 2026-10-23

Technical details

CVSS v3 Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H
Published: 2016-04-07
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2016-3947?

Is CVE-2016-3947 actively exploited?

Active exploitation of CVE-2016-3947 has not been confirmed. Its EPSS score was 14.6% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2016-3947?

CVE-2016-3947 has a CVSS v3 base score of 8.2 (HIGH severity), with vector string CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H.

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