How severe is CVE-2019-1964?

CVE-2019-1964 has a CVSS 3.x base score of 8.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2019-1964 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (78th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2019-1964?

CVE-2019-1964 affects Cisco Nx-os. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2019-1964?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2019-1964 published?

CVE-2019-1964 was published on 2019-08-28 and last updated on 2026-06-17.

CVE-2019-1964

CVE-2019-1964 is a high-severity vulnerability in Cisco Nx-os with a CVSS 3.x base score of 8.6. 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-20.

Key facts

Severity: High (CVSS 3.x base score 8.6)
CVSS v2: 7.8
EPSS exploit prediction: 2% (78th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Cisco Nx-os
Published: 2019-08-28
Last modified: 2026-06-17

Description

A vulnerability in the IPv6 traffic processing of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause an unexpected restart of the netstack process on an affected device. The vulnerability is due to improper validation of IPv6 traffic sent through an affected device. An attacker could exploit this vulnerability by sending a malformed IPv6 packet through an affected device. A successful exploit could allow the attacker to cause a denial of service (DoS) condition while the netstack process restarts. A sustained attack could lead to a reboot of the device.

Frequently asked questions

What is CVE-2019-1964?: A vulnerability in the IPv6 traffic processing of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause an unexpected restart of the netstack process on an affected device. The vulnerability is due to improper validation of IPv6 traffic sent through an affected device. An attacker could exploit this vulnerability by sending a malformed IPv6 packet through an affected device. A successful exploit could allow the attacker to cause a denial of service (DoS) condition while the netstack process restarts. A sustained attack could lead to a reboot of the device.
How severe is CVE-2019-1964?: CVE-2019-1964 has a CVSS 3.x base score of 8.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2019-1964 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (78th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2019-1964?: CVE-2019-1964 affects Cisco Nx-os. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2019-1964?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2019-1964 published?: CVE-2019-1964 was published on 2019-08-28 and last updated on 2026-06-17.

References

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190828-nxos-ipv6-dos

Affected products (1)

cpe:2.3:o:cisco:nx-os:*:*:*:*:*:*:*:*

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