CVE-2026-3591
MEDIUM EPSS 27.9%
Published Mar 25, 20263mo ago · Modified Jun 17, 20262w ago
5.4 CVSS 3.1
Published Mar 25, 2026 3mo ago
Last Modified Jun 17, 2026 2w ago
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.
CVSS Details
Base Score
Exploitability
Impact
Vector string
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N Attack Vector Network
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality Low
Integrity Low
Availability None
Threat Intelligence
EPSS Exploit Probability
27.9% percentile
Exploit & Patch Status
No Known Exploit
Patch Available
Weaknesses 2
CWE-305
CWE-562
Affected Products 2
References 3
- downloads.isc.org https://downloads.isc.org/isc/bind9/9.20.21
- downloads.isc.org https://downloads.isc.org/isc/bind9/9.21.20
- kb.isc.org https://kb.isc.org/docs/cve-2026-3591
Remediation
- downloads.isc.org https://downloads.isc.org/isc/bind9/9.20.21
- downloads.isc.org https://downloads.isc.org/isc/bind9/9.21.20