CVE-2025-30193
Denial of service via crafted TCP exchange
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 setMaxTCPQueriesPerConnection setting.
We would like to thank Renaud Allard for bringing this issue to our attention.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Denial of service via crafted TCP exchange
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 setMaxTCPQueriesPerConnection setting.
We would like to thank Renaud Allard for bringing this issue to our attention.
- Record
CVE-2025-30193- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-674
- Updated
- 2026-11-02
EUVDEUVD-2025-15818
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 setMaxTCPQueriesPerConnection setting.
We would like to thank Renaud Allard for bringing this issue to our attention.
- Record
EUVD-2025-15818- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-4q3h-v92p-gchj
In some circumstances, when DNSdist is configured to allow an unlimited number of queries on a...
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 setMaxTCPQueriesPerConnection setting.
We would like to thank Renaud Allard for bringing this issue to our attention.
- Record
GHSA-4q3h-v92p-gchj- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-674
- Updated
- 2026-11-02
NVD
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 setMaxTCPQueriesPerConnection setting.
We would like to thank Renaud Allard for bringing this issue to our attention.
- Record
CVE-2025-30193- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-674
- Updated
- 2026-11-02
OSVALPINE-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 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 setMaxTCPQueriesPerConnection setting.
We would like to thank Renaud Allard for bringing this issue to our attention.
- Record
ALPINE-CVE-2025-30193- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-03
OSV
Denial of service via crafted TCP exchange
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 setMaxTCPQueriesPerConnection setting.
We would like to thank Renaud Allard for bringing this issue to our attention.
- Record
CVE-2025-30193- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-674
- Updated
- 2026-11-02
Show 6 moreShow less
OSVDEBIAN-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 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 setMaxTCPQueriesPerConnection setting. We would like to thank Renaud Allard for bringing this issue to our attention.
- Record
DEBIAN-CVE-2025-30193- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVUBUNTU-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 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 setMaxTCPQueriesPerConnection setting. We would like to thank Renaud Allard for bringing this issue to our attention.
- Record
UBUNTU-CVE-2025-30193- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVSUSE-SU-2025:01743-1 No score
Security update for dnsdist
This update for dnsdist fixes the following issues:
Update to version 1.9.10.
- CVE-2025-30194: illegal memory access (double-free) when processing specially crafted DoH exchanges leads to a denial-of-service (bsc#1242028).
- CVE-2025-30193: stack exhaustion when processing too many queries on incoming TCP connections leads to a denial-of-service (bsc#1243378).
- Record
SUSE-SU-2025:01743-1- Updated
- 2026-11-02
OSVSUSE-SU-2025:01745-1 No score
Security update for dnsdist
This update for dnsdist fixes the following issues:
- CVE-2025-30193: stack exhaustion when processing too many queries on incoming TCP connections leads to a denial-of-service (bsc#1243378).
- Record
SUSE-SU-2025:01745-1- Updated
- 2026-11-02
OSVSUSE-SU-2025:01792-1 No score
Security update for dnsdist
This update for dnsdist fixes the following issues:
- CVE-2025-30193: stack exhaustion when processing too many queries on incoming TCP connections leads to a denial-of-service (bsc#1243378).
- Record
SUSE-SU-2025:01792-1- Updated
- 2026-11-02
OSVUSN-8037-1 No score
dnsdist vulnerabilities
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)
- Record
USN-8037-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
dnsdistAlpine:v3.21 |
before 1.9.10-r0 | 1.9.10-r0 |
dnsdistAlpine:v3.22 |
before 1.9.10-r0 | 1.9.10-r0 |
dnsdistAlpine:v3.23 |
before 1.9.10-r0 | 1.9.10-r0 |
dnsdistAlpine:v3.24 |
before 1.9.10-r0 | 1.9.10-r0 |
dnsdistDebian:12 |
All versions, plus listed versions 1.7.3-21.8.0-11.8.1-11.8.2-11.8.2-2 Show 31 moreShow less1.8.2-31.8.3-11.8.3-21.8.3-31.9.10-11.9.3-11.9.4-11.9.5-11.9.6-11.9.8-11.9.9-12.0.0-12.0.0-22.0.0-32.0.0-42.0.0-52.0.0-62.0.0~rc1-12.0.0~rc1-22.0.0~rc2-12.0.1-12.0.2-12.0.3-12.0.4-12.0.5-12.0.5-22.0.5-32.0.6-12.1.0-12.1.0-22.1.1-1 |
None known |
dnsdistDebian:13 |
before 1.9.10-1 | 1.9.10-1 |
dnsdistDebian:14 |
before 1.9.10-1 | 1.9.10-1 |
dnsdistSUSE:Linux Enterprise Module for Basesystem 15 SP7 |
before 1.9.10-150700.3.3.1 | 1.9.10-150700.3.3.1 |
dnsdistSUSE:Linux Enterprise Module for Basesystem 15 SP6 |
before 1.8.0-150400.9.6.1 | 1.8.0-150400.9.6.1 |
dnsdistSUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS |
before 1.8.0-150400.9.6.1 | 1.8.0-150400.9.6.1 |
Show 15 moreShow less
| Package | Affected | Fixed |
|---|---|---|
dnsdistSUSE:Linux Enterprise High Performance Computing 15 SP4-LTSS |
before 1.8.0-150400.9.6.1 | 1.8.0-150400.9.6.1 |
dnsdistSUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOS |
before 1.8.0-150400.9.6.1 | 1.8.0-150400.9.6.1 |
dnsdistSUSE:Linux Enterprise High Performance Computing 15 SP5-LTSS |
before 1.8.0-150400.9.6.1 | 1.8.0-150400.9.6.1 |
dnsdistSUSE:Linux Enterprise Server 15 SP4-LTSS |
before 1.8.0-150400.9.6.1 | 1.8.0-150400.9.6.1 |
dnsdistSUSE:Linux Enterprise Server 15 SP5-LTSS |
before 1.8.0-150400.9.6.1 | 1.8.0-150400.9.6.1 |
dnsdistSUSE:Linux Enterprise Server for SAP Applications 15 SP4 |
before 1.8.0-150400.9.6.1 | 1.8.0-150400.9.6.1 |
dnsdistSUSE:Linux Enterprise Server for SAP Applications 15 SP5 |
before 1.8.0-150400.9.6.1 | 1.8.0-150400.9.6.1 |
dnsdistSUSE:Manager Proxy 4.3 |
before 1.8.0-150400.9.6.1 | 1.8.0-150400.9.6.1 |
dnsdistSUSE:Manager Server 4.3 |
before 1.8.0-150400.9.6.1 | 1.8.0-150400.9.6.1 |
dnsdistopenSUSE:Leap 15.6 |
before 1.8.0-150400.9.6.1 | 1.8.0-150400.9.6.1 |
dnsdistSUSE:Linux Enterprise Server 15 SP3-LTSS |
before 1.8.0-150100.3.8.1 | 1.8.0-150100.3.8.1 |
dnsdistSUSE:Enterprise Storage 7.1 |
before 1.8.0-150100.3.8.1 | 1.8.0-150100.3.8.1 |
dnsdistUbuntu:Pro:22.04:LTS |
before 1.6.1-1ubuntu0.1~esm2, plus listed versions 1.5.1-3build21.6.1-1build11.6.1-1ubuntu0.1~esm1 |
1.6.1-1ubuntu0.1~esm2 |
dnsdistUbuntu:Pro:24.04:LTS |
before 1.8.3-2ubuntu0.1~esm1, plus listed versions 1.8.0-11.8.2-11.8.2-21.8.2-31.8.3-11.8.3-21.8.3-2build11.8.3-2build2 |
1.8.3-2ubuntu0.1~esm1 |
dnsdistUbuntu:25.10 |
before 1.9.10-1ubuntu0.1, plus listed versions 1.9.8-11.9.10-1 |
1.9.10-1ubuntu0.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, aliases, references | OSV | |
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2025-30193 is a high vulnerability (CVSS 7.5) in Powerdns Dnsdist, published May 20, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.62%, the 49th percentile. Fixed in dnsdist 1.9.10-r0.
References
dnsdist.org/security-advisories/powerdns-advisory-for-dnsdist-2025-03.html
nvd.nist.gov/vuln/detail/CVE-2025-30193
github.com/advisories/GHSA-4q3h-v92p-gchj
security.alpinelinux.org/vuln/CVE-2025-30193
repo.powerdns.com
Show 15 moreShow less
security-tracker.debian.org/tracker/CVE-2025-30193
suse.com/support/update/announcement/2025/suse-su-202501743-1
bugzilla.suse.com/1242028
ubuntu.com/security/CVE-2025-30193
cve.org/CVERecord?id=CVE-2025-30193