CVE-2026-40209
Denial of service via IXFR queries
CVSS Score
5.3
EPSS Score
0.0%
EPSS Percentile
0th
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.
| Vendor | powerdns |
| Product | dnsdist |
| Published | Jun 25, 2026 |
| Last Updated | Jun 25, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
Low
Affected Versions
PowerDNS / DNSdist
1.9.0 < 1.9.15 2.0.0 < 2.0.7
References
Credits
Qifan Zhang (Palo Alto Networks)