CVE-2026-3591

5.4 MEDIUM
Published: March 25, 2026 Modified: March 25, 2026
View on NVD

Description

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. This issue affects BIND 9 versions 9.20.0 through 9.20.20, 9.21.0 through 9.21.19, and 9.20.9-S1 through 9.20.20-S1. BIND 9 versions 9.18.0 through 9.18.46 and 9.18.11-S1 through 9.18.46-S1 are NOT affected.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://downloads.isc.org/isc/bind9/9.20.21
Source: security-officer@isc.org
https://downloads.isc.org/isc/bind9/9.21.20
Source: security-officer@isc.org
https://kb.isc.org/docs/cve-2026-3591
Source: security-officer@isc.org

3 reference(s) from NVD

Quick Stats

CVSS v3 Score
5.4 / 10.0
EPSS (Exploit Probability)
0.0%
5th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)