Allocation of Resources Without Limits or Throttling in dnsdist - CVE-2026-33595
Published: April 23, 2026
Vulnerability identifier: #VU126951
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-33595
CWE-ID: CWE-770
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to allocation of resources without limits or throttling in DoQ and DoH3 connection handling when generating many error responses over a single connection. A remote attacker can generate many error responses over a single DoQ or DoH3 connection to cause a denial of service.
Resources are not properly released until the end of the connection.
Affected software
dnsdist
Debian Linux
Fedora
dnsdist (Debian package)
dnsdist
Debian Linux
Fedora
dnsdist (Debian package)
dnsdist
How to mitigate CVE-2026-33595
Install security update from vendor's website.
dnsdist - addressed in versions 1.9.13, 2.0.4
dnsdist (Debian package) - update to 1.9.14-0+deb13u1
dnsdist - update to 2.0.6-1.el10_2
dnsdist (Debian package) - update to 1.9.14-0+deb13u1
dnsdist - update to 2.0.6-1.el10_2