Signal Handler Race Condition in PowerDNS Authoritative - CVE-2026-42002

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Main Vulnerability Database Vulnerabilities #VU131980

Signal Handler Race Condition in PowerDNS Authoritative - CVE-2026-42002

Published: May 20, 2026


Vulnerability identifier: #VU131980
CSH Severity: Medium
CVSS v4: 8.2 [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]
CVE-ID: CVE-2026-42002
CWE-ID: CWE-364
Exploitation vector: Remote access
Exploit availability: No public exploit available

Vulnerability details

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.


Affected software

PowerDNS Authoritative
Debian Linux
Fedora
pdns (Debian package)
pdns

How to mitigate CVE-2026-42002

Install security update from vendor's website.

PowerDNS Authoritative - addressed in versions 4.9.15, 5.0.5
pdns (Debian package) - update to 4.9.15-0+deb13u1
pdns - addressed in versions 5.0.5-1.el9, 5.0.5-1.el10_2, 5.0.5-1.el10_3, 5.0.5-1.fc43, 5.0.5-1.fc44

External References

Related Security Bulletins