CVE-2026-40211
Denial of service via crafted DoH3 queries
CVSS Score
5.3
EPSS Score
0.0%
EPSS Percentile
0th
An attacker can send crafted DNS over HTTP/3 queries, triggering an exception that prevents some buffer from being freed right away. The buffer will be freed at the end of the QUIC connection, but on some setups it might be possible to open enough concurrent DoH3 streams to trigger an out-of-memory condition, resulting in a denial of service.
| 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
Mehtab Zafar