CVE-2026-40211: Allocation of Resources Without Limits or Throttling in PowerDNS DNSdist
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.
CVE-2026-40211: Allocation of Resources Without Limits or Throttling in PowerDNS DNSdist
Description
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.
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: 6a3d2a1b4853345fc1f848fc
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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