PT-2026-42165 · Isc+3 · Bind 9+3

Published 2026-05-17 · Updated 2026-05-28 · CVE-2026-5950

Positive Technologies (AI Summary)

CVSS v3.1

5.3

Medium

Base vector

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

Name of the Vulnerable Software and Affected Versions BIND 9 versions 9.18.36 through 9.18.48 BIND 9 versions 9.20.8 through 9.20.22 BIND 9 versions 9.21.7 through 9.21.21 BIND 9 versions 9.18.36-S1 through 9.18.48-S1 BIND 9 versions 9.20.9-S1 through 9.20.22-S1

Description An unbounded resend loop exists in the resolver state machine during bad-server handling. A remote unauthenticated attacker can cause severe resource exhaustion by sending queries that trigger specific retry conditions.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Weakness Enumeration

CWE-606

Related Identifiers

CVE-2026-5950

ECHO-42EC-02DE-982E

OPENSUSE-SU-2026:10874-1

RHSA-2026:20334

USN-8293-1

Affected Products

Bind 9

Bind Server

Linuxmint

Ubuntu

References · 30

• https://ubuntu.com/security/CVE-2026-3592 · Vendor Advisory
• https://osv.dev/vulnerability/DEBIAN-CVE-2026-5950 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2026-5950 · Security Note
• https://ubuntu.com/security/notices/USN-8293-1 · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-5947 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2026-5950 · Vendor Advisory
• https://osv.dev/vulnerability/BELL-CVE-2026-5950 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2026-5950 · Vendor Advisory
• https://downloads.isc.org/isc/bind9/9.20.23 · Patch
• https://osv.dev/vulnerability/ALPINE-CVE-2026-5950 · Vendor Advisory
• https://osv.dev/vulnerability/USN-8293-1 · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-3593 · Vendor Advisory
• https://downloads.isc.org/isc/bind9/9.21.22 · Patch
• https://downloads.isc.org/isc/bind9/9.18.49 · Patch
• https://nvd.nist.gov/vuln/detail/CVE-2026-5950 · Security Note