Home / mailings [USN-8037-1] DNSdist vulnerabilities
Posted on 12 February 2026
Ubuntu Security==========================================================================Ubuntu Security Notice USN-8037-1
February 12, 2026
dnsdist vulnerabilities
==========================================================================
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 25.10
- Ubuntu 24.04 LTS
- Ubuntu 22.04 LTS
Summary:
Several security issues were fixed in dnsdist.
Software Description:
- dnsdist: A highly DNS-, DoS- and abuse-aware loadbalancer
Details:
It was discovered that HTTP/2, which is used/vendored by DNSdist, did not
properly account for resources when handling client-triggered stream
resets. An attacker could possibly use this issue to cause a
denial of service. (CVE-2025-8671)
It was discovered that DNSdist did not properly manage memory limits when
handling an unlimited number of queries on a single TCP connection. An
attacker could possibly use this issue to cause a denial of service.
(CVE-2025-30193)
It was discovered that DNSdist, when configured with the nghttp2 library,
did not correctly process certain DNS over HTTPS queries. An attacker
could possibly use this cause a denial of service. (CVE-2025-30187)
Update instructions:
The problem can be corrected by updating your system to the following
package versions:
Ubuntu 25.10
dnsdist 1.9.10-1ubuntu0.1
Ubuntu 24.04 LTS
dnsdist 1.8.3-2ubuntu0.1~esm1
Available with Ubuntu Pro
Ubuntu 22.04 LTS
dnsdist 1.6.1-1ubuntu0.1~esm2
Available with Ubuntu Pro
In general, a standard system update will make all the necessary changes.
References:
https://ubuntu.com/security/notices/USN-8037-1
CVE-2025-30187, CVE-2025-30193, CVE-2025-8671
Package Information:
https://launchpad.net/ubuntu/+source/dnsdist/1.9.10-1ubuntu0.1
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