Is CVE-2021-4186 in the CISA KEV catalog?

No. CVE-2021-4186 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-4186?

CVE-2021-4186 has a CVSS v3 base score of 6.3 (MEDIUM).

What is the EPSS score for CVE-2021-4186?

CVE-2021-4186 has an EPSS score of 2.21% (80th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-4186?

Upgrade wireshark on debian 11 to 3.4.16-0+deb11u1 or later. Fixes are available for 9 affected products.

CVE & CISA-KEV Catalog

CVE-2021-4186

MEDIUMEPSS 80th pctl

6.3

CVSS v3

NVD

Description

Crash in the Gryphon dissector in Wireshark 3.4.0 to 3.4.10 allows denial of service via packet injection or crafted capture file

CWE-476NULL Pointer Dereference

How to fix

Remediation Available

wiresharkDebian

Fixed in:3.4.16-0+deb11u1CVE-2021-4186

Fixed in:3.6.0-1CVE-2021-4186

libwireshark11Ubuntu

Fixed in:2.6.10-1~ubuntu14.04.0~esm3USN-7552-1

Fixed in:2.6.10-1~ubuntu16.04.0+esm2USN-7552-1

Fixed in:2.6.10-1~ubuntu18.04.0+esm2USN-7552-1

libwireshark13Ubuntu

Fixed in:3.2.3-1ubuntu0.1~esm2USN-7552-1

libwireshark15Ubuntu

Fixed in:3.6.2-2ubuntu0.1~esm1USN-7552-1

tsharkUbuntu

Fixed in:2.6.10-1~ubuntu14.04.0~esm3USN-7552-1

Fixed in:2.6.10-1~ubuntu16.04.0+esm2USN-7552-1

Fixed in:2.6.10-1~ubuntu18.04.0+esm2USN-7552-1

Fixed in:3.2.3-1ubuntu0.1~esm2USN-7552-1

Fixed in:3.6.2-2ubuntu0.1~esm1USN-7552-1

wiresharkUbuntu

Fixed in:2.6.10-1~ubuntu14.04.0~esm3USN-7552-1

Fixed in:2.6.10-1~ubuntu16.04.0+esm2USN-7552-1

Fixed in:2.6.10-1~ubuntu18.04.0+esm2USN-7552-1

Fixed in:3.2.3-1ubuntu0.1~esm2USN-7552-1

Fixed in:3.6.2-2ubuntu0.1~esm1USN-7552-1

wireshark-commonUbuntu

Fixed in:2.6.10-1~ubuntu14.04.0~esm3USN-7552-1

Fixed in:2.6.10-1~ubuntu16.04.0+esm2USN-7552-1

Fixed in:2.6.10-1~ubuntu18.04.0+esm2USN-7552-1

Fixed in:3.2.3-1ubuntu0.1~esm2USN-7552-1

Fixed in:3.6.2-2ubuntu0.1~esm1USN-7552-1

wireshark-gtkUbuntu

Fixed in:2.6.10-1~ubuntu14.04.0~esm3USN-7552-1

Fixed in:2.6.10-1~ubuntu16.04.0+esm2USN-7552-1

Fixed in:2.6.10-1~ubuntu18.04.0+esm2USN-7552-1

Fixed in:3.2.3-1ubuntu0.1~esm2USN-7552-1

Fixed in:3.6.2-2ubuntu0.1~esm1USN-7552-1

wireshark-qtUbuntu

Fixed in:2.6.10-1~ubuntu14.04.0~esm3USN-7552-1

Fixed in:2.6.10-1~ubuntu16.04.0+esm2USN-7552-1

Fixed in:2.6.10-1~ubuntu18.04.0+esm2USN-7552-1

Fixed in:3.2.3-1ubuntu0.1~esm2USN-7552-1

Fixed in:3.6.2-2ubuntu0.1~esm1USN-7552-1

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionRequired

ScopeUnchanged

Impact

ConfidentialityLow

IntegrityLow

AvailabilityLow

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L

Exploit Intelligence

2.21%probability of exploitation in 30 days

80thpercentile

Elevated risk: more likely to be exploited than 80% of all known CVEs.

References

Exploit1

gitlab.com

Vendor Advisory1

wireshark.org

Third-Party Advisory2

Other references5

Related Vulnerabilities

Other CWE-476 (NULL Pointer Dereference) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2023-21758	High	7.5	92%	-	Fix
CVE-2023-21547	High	7.5	88%	-	Fix
CVE-2014-3470	Medium	4.3	86%	-	Fix
CVE-2021-44224	High	8.2	82%	-	Fix
CVE-2016-0742	High	7.5	82%	-	Fix
CVE-2009-1386	Medium	5.0	80%	-	Fix

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-11-03.