CVE-2026-40211 Affecting dnsdist package, versions <1.9.15-0+deb13u1
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-ECHOLATEST-DNSDIST-18578978
- published7 Aug 2026
- disclosed25 Jun 2026
Introduced: 25 Jun 2026
CVE-2026-40211 (opens in a new tab)How to fix?
Upgrade Echo:latest dnsdist to version 1.9.15-0+deb13u1 or higher.
NVD Description
Note: Versions mentioned in the description apply only to the upstream dnsdist package and not the dnsdist package as distributed by Echo.
See How to fix? for Echo:latest relevant fixed versions and status.
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.