SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAwaiting Analysis

CVE-2026-19666

On a resolver configured to use ``dns64``, if an applicable answer from the authoritative server is malformed in a specific way, the resolver `named` process will exit unexpectedly.

HIGH 7.5EPSS 0.57%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.57%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

On a resolver configured to use ``dns64``, if an applicable answer from the authoritative server is malformed in a specific way, the resolver `named` process will exit unexpectedly. This issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.27-S1.

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
0.57% probability · 47th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-416
Source
security-officer@isc.org
EPSS trend
0%3%5%27 October 2026: 0.57%27 October 202627 October 2026

EPSS 0.6% since 27 October 2026; no change recorded yet. 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.