CVE-2025-30193Uncontrolled Recursion in Dnsdist

Severity
7.5HIGHNVD
OSV3.7
EPSS
0.2%
top 63.81%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
Timeline
PublishedMay 20
Latest updateFeb 12

Description

In some circumstances, when DNSdist is configured to allow an unlimited number of queries on a single, incoming TCP connection from a client, an attacker can cause a denial of service by crafting a TCP exchange that triggers an exhaustion of the stack and a crash of DNSdist, causing a denial of service. The remedy is: upgrade to the patched 1.9.10 version. A workaround is to restrict the maximum number of queries on incoming TCP connections to a safe value, like 50, via the setMaxTCPQueriesPer

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitability: 3.9 | Impact: 3.6

Affected Packages2 packages

Debianpowerdns/dnsdist< 1.9.10-1+1
Ubuntupowerdns/dnsdist< 1.9.10-1ubuntu0.1+2

🔴Vulnerability Details

4
OSV
dnsdist vulnerabilities2026-02-12
OSV
CVE-2025-30193: In some circumstances, when DNSdist is configured to allow an unlimited number of queries on a single, incoming TCP connection from a client, an attac2025-05-20
CVEList
Denial of service via crafted TCP exchange2025-05-20
GHSA
GHSA-4q3h-v92p-gchj: In some circumstances, when DNSdist is configured to allow an unlimited number of queries on a single, incoming TCP connection from a client, an attac2025-05-20

📋Vendor Advisories

2
Ubuntu
DNSdist vulnerabilities2026-02-12
Debian
CVE-2025-30193: dnsdist - In some circumstances, when DNSdist is configured to allow an unlimited number o...2025
CVE-2025-30193 — Uncontrolled Recursion in Dnsdist | cvebase