SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2020-16899

<p>A denial of service vulnerability exists when the Windows TCP/IP stack improperly handles ICMPv6 Router Advertisement packets.

HIGH 7.5EPSS 13.5%

Does this matter?

EPSS puts the probability of exploitation in the next 30 days at 13.5%, higher than 96% of all known CVEs. Patch or mitigate before the next change window.

Description

<p>A denial of service vulnerability exists when the Windows TCP/IP stack improperly handles ICMPv6 Router Advertisement packets. An attacker who successfully exploited this vulnerability could cause a target system to stop responding.</p> <p>To exploit this vulnerability, an attacker would have to send specially crafted ICMPv6 Router Advertisement packets to a remote Windows computer. The vulnerability would not allow an attacker to execute code or to elevate user rights directly.</p> <p>The update addresses the vulnerability by correcting how the Windows TCP/IP stack handles ICMPv6 Router Advertisement packets.</p>

CVSS 3.1
7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
13.45% probability · 96th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Affected
microsoft/windows 10 · microsoft/windows server 2016 · microsoft/windows server 2019
Source
secure@microsoft.com
EPSS trend
0%8%15%3 November 2026: 13.45%3 November 20263 November 2026

EPSS 13.5% since 3 November 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.