CVE-2026-3591

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.

CVSS v3 5.4 MEDIUM

5.4^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 2.5

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://downloads.isc.org/isc/bind9/9.20.21
https://downloads.isc.org/isc/bind9/9.21.20
https://kb.isc.org/docs/cve-2026-3591

Configurations

No configuration.

History

No history.

Information

Published : 2026-03-25 14:16

Updated : 2026-03-25 15:41

NVD link : CVE-2026-3591

Mitre link : CVE-2026-3591

CVE.ORG link : CVE-2026-3591

JSON object : View

Products Affected

No product.

CWE

CWE-305

Authentication Bypass by Primary Weakness

CWE-562

Return of Stack Variable Address

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