How severe is CVE-2021-4186?

CVE-2021-4186 has a CVSS 3.x base score of 6.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability low.

Is CVE-2021-4186 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (80th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-4186?

CVE-2021-4186 primarily affects Wireshark. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-4186?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-4186 published?

CVE-2021-4186 was published on 2021-12-30 and last updated on 2026-06-17.

CVE-2021-4186

CVE-2021-4186 is a medium-severity vulnerability in Wireshark with a CVSS 3.x base score of 6.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-476.

Key facts

Severity: Medium (CVSS 3.x base score 6.3)
CVSS v2: 5.0
EPSS exploit prediction: 2% (80th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-476
Affected product: Wireshark
Published: 2021-12-30
Last modified: 2026-06-17

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

Frequently asked questions

What is CVE-2021-4186?: 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
How severe is CVE-2021-4186?: CVE-2021-4186 has a CVSS 3.x base score of 6.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability low.
Is CVE-2021-4186 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (80th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-4186?: CVE-2021-4186 primarily affects Wireshark. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-4186?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-4186 published?: CVE-2021-4186 was published on 2021-12-30 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:a:wireshark:wireshark:*:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*

More vulnerabilities in Wireshark

CVE-2011-0444 — Critical (CVSS 10.0): Buffer overflow in the MAC-LTE dissector (epan/dissectors/packet-mac-lte.c) in Wireshark 1.2.0 through 1.2.13 and 1.4.0…
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CVE-2010-2994 — Critical (CVSS 10.0): Stack-based buffer overflow in the ASN.1 BER dissector in Wireshark 0.10.13 through 1.0.14 and 1.2.0 through 1.2.9 has…
CVE-2009-1266 — Critical (CVSS 10.0): Unspecified vulnerability in Wireshark before 1.0.7 has unknown impact and attack vectors.
CVE-2009-1210 — Critical (CVSS 10.0): Format string vulnerability in the PROFINET/DCP (PN-DCP) dissector in Wireshark 1.0.6 and earlier allows remote…
CVE-2008-3146 — Critical (CVSS 10.0): Multiple buffer overflows in packet_ncp2222.inc in Wireshark (formerly Ethereal) 0.9.7 through 1.0.2 allow attackers to…

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