CVE-2026-3593

7.4 HIGH

A use-after-free vulnerability exists within the DNS-over-HTTPS implementation

Published: 2026-05-20 · Last updated: 2026-05-21

Severity and scoring

CVSS: 7.4 HIGH
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H
CWE: CWE-416

Affected products

Vendor	Product
isc	bind

Description

A use-after-free vulnerability exists within the DNS-over-HTTPS implementation. This issue affects BIND 9 versions 9.20.0 through 9.20.22, 9.21.0 through 9.21.21, and 9.20.9-S1 through 9.20.22-S1. BIND 9 versions 9.18.0 through 9.18.48 and 9.18.11-S1 through 9.18.48-S1 are NOT affected.

Source: NVD

References

[NVD]https://nvd.nist.gov/vuln/detail/CVE-2026-3593
[Patch]https://downloads.isc.org/isc/bind9/9.20.23
[Patch]https://downloads.isc.org/isc/bind9/9.21.22
[Vendor advisory]https://kb.isc.org/docs/cve-2026-3593

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