CVE-2026-3593

Heap use-after-free vulnerability in BIND 9 DNS-over-HTTPS implementation

CVE-2026-3593 is fixed in 6 products on 1 platform, first by bind9 1:9.20.18-1ubuntu2.1, released May 19, 2026. It is not reported as exploited. Patch Radar priority: High.

High

CVSS

9.8

Important

Exploitation

None reported

No vendor assessment

CISA KEV

Not listed

Not in the Known Exploited Vulnerabilities catalog

EPSS

0.0154

75th percentile

This update for bind fixes the following issues - CVE-2026-3039: BIND 9 server memory exhaustion during GSS-API TKEY negotiation (bsc#1265591). - CVE-2026-3592: Amplification vulnerabilities via self-pointed glue records (bsc#1265592). - CVE-2026-5946: Invalid handling of CLASS != IN (bsc#1265594). - CVE-2026-5950: Unbounded resend loop in BIND 9 resolver (bsc#1265596). - CVE-2026-3593: Heap use-after-free vulnerability in BIND 9 DNS-over-HTTPS implementation (bsc#1265593). Changes for bind: - Update to release 9.18.49

Where it's fixed

Product	Fixed in	Fix	Released
Linux
bind · opensuse-leap 16.0	9.20.23-160000.1.1	OPENSUSE-SU-2026:21123-1	Jun 20, 2026
bind · sles 15.6	9.18.49-150600.3.26.1	SUSE-SU-2026:2676-1	Jun 29, 2026
bind · sles 15.7	9.20.23-150700.3.25.1	SUSE-SU-2026:2673-1	Jul 2, 2026
bind · sles 16.0	9.20.23-160000.1.1	SUSE-SU-2026:22198-1	Jun 20, 2026
bind9 · Debian 13.5 (trixie)	1:9.20.23-1~deb13u1	DEBIAN-CVE-2026-3593	May 27, 2026
bind9 · Debian 14	1:9.20.23-1	DEBIAN-CVE-2026-3593	May 27, 2026
bind9 · Ubuntu 25.10 (questing)	1:9.20.11-1ubuntu2.4	bind9 1:9.20.11-1ubuntu2.4	May 27, 2026
bind9 · Ubuntu 26.04.1 LTS (resolute)	1:9.20.18-1ubuntu2.1	bind9 1:9.20.18-1ubuntu2.1	May 19, 2026
bind9-dnsutils · Ubuntu 25.10 (questing)	1:9.20.11-1ubuntu2.4	bind9-dnsutils 1:9.20.11-1ubuntu2.4	May 27, 2026
bind9-dnsutils · Ubuntu 26.04.1 LTS (resolute)	1:9.20.18-1ubuntu2.1	bind9-dnsutils 1:9.20.18-1ubuntu2.1	May 19, 2026
bind9-host · Ubuntu 25.10 (questing)	1:9.20.11-1ubuntu2.4	bind9-host 1:9.20.11-1ubuntu2.4	May 27, 2026
bind9-host · Ubuntu 26.04.1 LTS (resolute)	1:9.20.18-1ubuntu2.1	bind9-host 1:9.20.18-1ubuntu2.1	May 19, 2026
bind9-libs · Ubuntu 25.10 (questing)	1:9.20.11-1ubuntu2.4	bind9-libs 1:9.20.11-1ubuntu2.4	May 27, 2026
bind9-libs · Ubuntu 26.04.1 LTS (resolute)	1:9.20.18-1ubuntu2.1	bind9-libs 1:9.20.18-1ubuntu2.1	May 19, 2026
bind9-utils · Ubuntu 25.10 (questing)	1:9.20.11-1ubuntu2.4	bind9-utils 1:9.20.11-1ubuntu2.4	May 27, 2026
bind9-utils · Ubuntu 26.04.1 LTS (resolute)	1:9.20.18-1ubuntu2.1	bind9-utils 1:9.20.18-1ubuntu2.1	May 19, 2026

Details

Published
May 19, 2026
Weakness
Use After Free
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Vendor advisory
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-3593

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