CVE-2026-3593
bind: Heap use-after-free vulnerability in BIND 9 DNS-over-HTTPS implementation
Severity
ImportantRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · May 21, 2026
Updated · November 5, 2026
Description
A flaw was found in the BIND (Berkeley Internet Name Domain) DNS-over-HTTPS implementation. A remote attacker could send specially crafted HTTP/2 traffic to a DNS-over-HTTPS endpoint, leading to a use-after-free vulnerability. This could trigger memory corruption, potentially allowing the attacker to cause a denial of service or, in some cases, execute arbitrary code.
Statement
Important: A heap use-after-free vulnerability in BIND's DNS-over-HTTPS implementation allows a remote attacker to trigger memory corruption by sending crafted HTTP/2 traffic to a DNS-over-HTTPS endpoint. This affects both authoritative servers and resolvers configured to use DNS-over-HTTPS, potentially leading to denial of service or other impacts.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
CVSS / CWE
CVSS 3.1 · 7.4CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H
CWE-825 · Expired Pointer Dereference