ISC BIND 9.20.0 < 9.20.21 / 9.20.9-S1 < 9.20.21-S1 / 9.21.0 < 9.21.20 Vulnerability (cve-2026-3591)

medium Nessus Plugin ID 303596

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-2026-3591 advisory.

- A use-after-return vulnerability exists in the named server when handling DNS queries signed with SIG(0). Using a specially-crafted DNS request, an attacker may be able to cause an ACL to improperly (mis)match an IP address. In a default-allow ACL (denying only specific IP addresses), this may lead to unauthorized access. Default-deny ACLs should fail-secure.An attacker may be able to cause an ACL to improperly (mis)match an IP address. In a default-allow ACL (denying only specific IP addresses), this may lead to unauthorized access. - Authoritative servers are affected by this vulnerability.
- Resolvers are affected by this vulnerability. Authoritative servers are affected by this vulnerability. Resolvers are affected by this vulnerability. (CVE-2026-3591)

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 9.20.21 / 9.20.21-S1 / 9.21.20 or later.

Plugin Details

Severity: Medium

ID: 303596

File Name: bind9_92120_cve-2026-3591.nasl

Version: 1.1

Type: remote

Family: DNS

Published: 3/25/2026

Updated: 3/25/2026

Configuration: Enable paranoid mode

Supported Sensors: Nessus

Risk Information

CVSS v2

Risk Factor: Medium

Base Score: 5.5

Temporal Score: 4.1

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

CVSS Score Source: CVE-2026-3591

CVSS v3

Risk Factor: Medium

Base Score: 5.4

Temporal Score: 4.7

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

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

Vulnerability Information

CPE: cpe:/a:isc:bind

Required KB Items: bind/version, Settings/ParanoidReport

Exploit Ease: No known exploits are available

Patch Publication Date: 3/25/2026

Vulnerability Publication Date: 3/25/2026

Reference Information

CVE: CVE-2026-3591

Detections

Analytics