Use-after-free in ISC BIND - CVE-2026-5947
Published: May 22, 2026
Vulnerability identifier: #VU132115
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-5947
CWE-ID: CWE-416
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: ISC
Affected software:
ISC BIND
ISC BIND
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to use-after-free in SIG(0) validation when processing a DNS message signed with SIG(0) while the recursive-clients limit is reached during a query flood. A remote attacker can send specially crafted DNS traffic to cause a denial of service.
Both authoritative servers and resolvers are affected.
How to mitigate CVE-2026-5947
Install security update from vendor's website.