ExploitedIn CISA KEVFix available

CVE-2016-6366

Q: Is CVE-2016-6366 actively exploited?

Yes. CVE-2016-6366 is on the CISA Known Exploited Vulnerabilities (KEV) catalog, meaning it has been confirmed as actively exploited in the wild. CISA requires federal agencies to patch by 2022-06-14.

Q: What is the CVSS score for CVE-2016-6366?

CVE-2016-6366 has a CVSS v3 base score of 8.8 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Exploitation confirmed. First attested on 2022-05-24 by CISA-ADP, CISA KEV, GCVE · kevintel.

Published2016-08-18
Fixed in9.6.1\(11\) · 9.4.3\(8\) · 9.3.3\(10\) · 9.2.4\(14\) · 9.1.7\(9\) · 9.0.4.40
WeaknessCWE-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

Buffer overflow in Cisco Adaptive Security Appliance (ASA) Software through 9.4.2.3 on ASA 5500, ASA 5500-X, ASA Services Module, ASA 1000V, ASAv, Firepower 9300 ASA Security Module, PIX, and FWSM devices allows remote authenticated users to execute arbitrary code via crafted IPv4 SNMP packets, aka Bug ID CSCva92151 or EXTRABACON.

Timeline

dates in UTC

2016-08-1818:59CVE publishedNVD
2022-05-24Listed as exploited by GCVEGCVE
2022-05-24Exploitation first reportedCISA KEV
2022-05-24Added to the CISA KEV catalogCISA KEV
2024-11-0817:39SSVC exploitation set to activeCISA-ADP
2026-10-2319:23First public proof of conceptPoC-in-GitHub
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-2016-6366?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2016-6366?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Cisco ASAversion to verify

Branch	Affected	Fixed in	Source
9.6	≥ 9.6.0, < 9.6.1\(11\)	9.6.1\(11\)	NVD
9.4	≥ 9.4.0.115, < 9.4.3\(8\)	9.4.3\(8\)	NVD
9.3	≥ 9.3.0, < 9.3.3\(10\)	9.3.3\(10\)	NVD
9.2	≥ 9.2.0, < 9.2.4\(14\)	9.2.4\(14\)	NVD
9.1	≥ 9.1.1, < 9.1.7\(9\)	9.1.7\(9\)	NVD
9.0	≥ 7.2.1, < 9.0.4.40	9.0.4.40	NVD
9.5	≥ 9.5.0, ≤ 9.5\(3\)	no fix published	NVD

Cisco asa 1000v cloud firewall software

Branch	Affected	Fixed in	Source
8.7	= 8.7.1	no fix published	NVD
8.7	= 8.7.1.1	no fix published	NVD

Cisco pix firewall softwareversion to verify

Branch	Affected	Fixed in	Source
—	all versions	no fix published	NVD

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

Fix

Update Cisco ASA to 9.6.1\(11\) · 9.4.3\(8\) · 9.3.3\(10\) · 9.2.4\(14\) · 9.1.7\(9\) · 9.0.4.40
CISA’s required action: Apply updates per vendor instructions.due 2022-06-14

Advisories and patches

blogs.cisco.comVendor Advisory
tools.cisco.comVendor Advisory
tools.cisco.comVendor Advisory

Detection

read 2026-10-23 19:23 UTC

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: 1 repository, unverifiedRiskSense-Ops/CVE-2016-6366

CISA Known Exploited Vulnerability

Date Added: 2022-05-24
Patch Due Date: 2022-06-14
Ransomware Use: Unknown
Required Action: Apply updates per vendor instructions.

Sources

CISA KEVKEV entry2022-05-24
GCVEexploitation2022-05-24
CISA-ADPSSVC decisionactive2024-11-08
OpenCVESSVC decisionactive—
CISA-ADPCVSS 3.18.82024-11-08
NVDCVSS 3.18.8read 2026-10-23
NVDCVSS 2.08.5read 2026-10-23
CISA-ADPweakness (CWE)CWE-1202024-11-08
NVDweakness (CWE)CWE-120read 2026-10-23
FIRST EPSSEPSS score87.6 %read 2026-10-23
PoC-in-GitHubproof of concept1read 2026-10-23

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Published: 2016-08-18
Last Modified: 2026-06-17
NVD status: Analyzed

Frequently asked questions

What is CVE-2016-6366?

Is CVE-2016-6366 actively exploited?

Yes. CVE-2016-6366 is on the CISA Known Exploited Vulnerabilities (KEV) catalog, meaning it has been confirmed as actively exploited in the wild. CISA requires federal agencies to patch by 2022-06-14.

What is the CVSS score for CVE-2016-6366?

CVE-2016-6366 has a CVSS v3 base score of 8.8 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

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