CVE-2026-40209: Missing Release of Resource after Effective Lifetime in PowerDNS DNSdist
An attacker might be able to cause outgoing TCP connections to backend to be stuck until a timeout occurs instead of being released immediately, by sending IXFR queries. This could be used to cause a denial of service if there is a limit to the number of concurrent connections to this backend, or if the process runs out of file descriptors.
CVE-2026-40209: Missing Release of Resource after Effective Lifetime in PowerDNS DNSdist
Description
An attacker might be able to cause outgoing TCP connections to backend to be stuck until a timeout occurs instead of being released immediately, by sending IXFR queries. This could be used to cause a denial of service if there is a limit to the number of concurrent connections to this backend, or if the process runs out of file descriptors.
CVSS v3.1
Score 5.3medium
Affected software
pkg:github/dnsdistRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- OX
- Date Reserved
- 2026-04-10T07:11:39.060Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a3d2a1b4853345fc1f848f6
Added to database: 06/25/2026, 13:16:11 UTC
Last updated: 06/25/2026, 13:16:11 UTC
Views: 1
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