ISC BIND 9.20.0 < 9.20.23 / 9.20.9-S1 < 9.20.23-S1 / 9.21.0 < 9.21.22 Vulnerability (cve-2026-3593)

critical Nessus Plugin ID 315660

Synopsis

The remote name server is affected by a vulnerability vulnerability.

Description

The version of ISC BIND installed on the remote host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the cve-2026-3593 advisory.

- A use-after-free vulnerability exists within the DNS-over-HTTPS implementation. This issue affects BIND 9 versions 9.20.0 through 9.20.22, 9.21.0 through 9.21.21, and 9.20.9-S1 through 9.20.22-S1. BIND 9 versions 9.18.0 through 9.18.48 and 9.18.11-S1 through 9.18.48-S1 are NOT affected. (CVE-2026-3593)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Upgrade to ISC BIND version 9.20.23 / 9.20.23-S1 / 9.21.22 or later.

See Also

https://kb.isc.org/v1/docs/cve-2026-3593

Plugin Details

Severity: Critical

ID: 315660

File Name: bind9_92122_cve-2026-3593.nasl

Version: 1.4

Type: Remote

Family: DNS

Published: 5/20/2026

Updated: 5/26/2026

Configuration: Enable paranoid mode

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: Critical

Base Score: 10

Temporal Score: 7.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

CVSS Score Source: CVE-2026-3593

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/a:isc:bind

Required KB Items: Settings/ParanoidReport, bind/version

Exploit Ease: No known exploits are available

Patch Publication Date: 5/20/2026

Vulnerability Publication Date: 5/20/2026

Reference Information

CVE: CVE-2026-3593

IAVA: 2026-A-0498