PT-2026-27775 · Isc+2 · Bind+2

Published 2026-01-01 · Updated 2026-05-21 · CVE-2026-3591

Positive Technologies (AI Summary)

CVSS v3.1

5.4

Medium

Base vector

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

Name of the Vulnerable Software and Affected Versions BIND versions 9.20.0 through 9.20.20 BIND versions 9.21.0 through 9.21.19 BIND versions 9.20.9-S1 through 9.20.20-S1

Description A use-after-return issue exists in the named server when processing DNS queries signed with SIG(0). A crafted DNS request could cause an Access Control List (ACL) to incorrectly match an IP address. In a default-allow ACL, this may result in unauthorized access.

Recommendations Update BIND to a version later than 9.20.20. Update BIND to a version later than 9.21.19. Update BIND to a version later than 9.20.20-S1.

Fix

Weakness Enumeration

CWE-305

CWE-562

Related Identifiers

CVE-2026-3591

OPENSUSE-SU-2026:10448-1

OPENSUSE-SU-2026:20550-1

RHSA-2026:6935

SUSE-SU-2026:1351-1

SUSE-SU-2026:21204-1

USN-8124-1

Affected Products

Bind

Linuxmint

Ubuntu

References · 38

• https://cve.org/CVERecord?id=CVE-2026-3591 · Security Note
• https://osv.dev/vulnerability/DEBIAN-CVE-2026-3591 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-3591 · Security Note
• https://osv.dev/vulnerability/openSUSE-SU-2026:10448-1 · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-3119 · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-3104 · Vendor Advisory
• https://kb.isc.org/docs/cve-2026-3591 · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-3591 · Vendor Advisory
• https://downloads.isc.org/isc/bind9/9.20.21 · Patch
• https://downloads.isc.org/isc/bind9/9.21.20 · Patch
• https://security-tracker.debian.org/tracker/CVE-2026-3591 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2026-3591 · Vendor Advisory
• https://osv.dev/vulnerability/ALPINE-CVE-2026-3591 · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-1519 · Vendor Advisory
• https://osv.dev/vulnerability/USN-8124-1 · Vendor Advisory