Signal Handler Race Condition in PowerDNS Authoritative - CVE-2026-42002
Published: May 20, 2026
Vulnerability identifier: #VU131980
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-42002
CWE-ID: CWE-364
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: PowerDNS.COM B.V.
Affected software:
PowerDNS Authoritative
PowerDNS Authoritative
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to race conditions in GSS-TSIG code when processing concurrent TKEY queries for the same key. A remote attacker can send concurrent TKEY queries for the same key to cause a denial of service.
Only deployments with gss-tsig support enabled are vulnerable.
How to mitigate CVE-2026-42002
Install security update from vendor's website.