VulnerabilityPublished 31 Mar 2026

CVE-2026-24030: PowerDNS DNSdist · Uncontrolled Memory Allocation

Affects PowerDNS DNSdistSource CVE Database V5

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Not known to be exploited · CVSS 5.3 Medium : upgrade to 2.0.3 or 1.9.12 when convenient.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 3.1 base score

5.3Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.5% chance of exploitation in 30 days – higher than 46% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 2.0.3, 1.9.12

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: Low

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 31 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade DNSdist and dnsdist to 2.0.3 or 1.9.12.

Affected software

Product	Affected	Fixed in
PowerDNSDNSdist	Affected >=2.0.0 <2.0.3	Fixed in 2.0.3
PowerDNSDNSdist	Affected >=1.9.0 <1.9.12	Fixed in 1.9.12
GitHubdnsdist`pkg:github/dnsdist`Other threats	Affected >=1.9.0 <1.9.12 >=2.0.0 <2.0.3	Fixed in 1.9.12 2.0.3

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

To mitigate CVE-2026-24030, organizations should upgrade PowerDNS DNSdist to versions beyond 2.0.0 where the vulnerability is addressed. If immediate patching is not possible, administrators should consider disabling DNS over QUIC and DNS over HTTP/3 protocols in DNSdist configurations to prevent exploitation vectors. Implementing resource limits and memory usage monitoring on DNSdist processes can help detect and contain abnormal memory consumption early. Deploying DNSdist behind network-level protections such as rate limiting, firewall rules, or DDoS mitigation services can reduce exposure to malicious traffic exploiting this vulnerability. Additionally, segregating DNSdist instances handling QUIC/HTTP3 traffic from critical infrastructure can limit blast radius. Regularly reviewing DNSdist logs for unusual QUIC connection closures or memory exceptions can aid in early detection of exploitation attempts. Finally, organizations should maintain updated incident response plans for DNS service disruptions to minimize operational impact.

Description

An attacker might be able to trick DNSdist into allocating too much memory while processing DNS over QUIC or DNS over HTTP/3 payloads, resulting in a denial of service. In setups with a large quantity of memory available this usually results in an exception and the QUIC connection is properly closed, but in some cases the system might enter an out-of-memory state instead and terminate the process.

Impact

The primary impact of CVE-2026-24030 is denial of service against DNS infrastructure using PowerDNS DNSdist. Successful exploitation can cause DNSdist to consume excessive memory, leading to process termination or system instability. This disrupts DNS resolution services, potentially affecting large numbers of users and dependent applications. Organizations relying on DNSdist for DNS load balancing or proxying, especially in high-availability or internet-facing scenarios, may experience outages or degraded performance. The disruption can affect internal networks, cloud services, and public-facing domains, impacting business operations, customer access, and security monitoring reliant on DNS. While the vulnerability does not compromise data confidentiality or integrity, the availability impact can be significant, particularly for service providers, enterprises, and critical infrastructure operators. The ease of remote exploitation without authentication increases the risk of widespread denial of service attacks targeting DNS services globally.

Summary

CVE-2026-24030 is a vulnerability affecting PowerDNS DNSdist versions 1.9.0 and 2.0.0, where the software improperly manages memory allocation when handling DNS queries over QUIC or DNS over HTTP/3 protocols. Specifically, an attacker can craft malicious DNS payloads that cause DNSdist to allocate excessive amounts of memory. This uncontrolled memory allocation can lead to denial of service conditions by exhausting available memory resources. In environments with large memory pools, DNSdist typically throws an exception and closes the QUIC connection properly, mitigating impact. However, in some configurations, the system may run out of memory entirely, causing the DNSdist process to terminate unexpectedly. This results in service disruption as DNSdist is often deployed as a load balancer or DNS proxy in critical DNS infrastructure. The vulnerability is remotely exploitable without requiring authentication or user interaction, increasing its risk profile. Although no active exploits have been reported, the vulnerability's nature makes it a potential target for denial of service attacks against DNS infrastructure relying on DNSdist. The CVSS v3.1 base score is 5.3, reflecting medium severity due to the lack of impact on confidentiality or integrity but notable availability disruption potential.

CWE-789Memory Allocation with Excessive Size Value (opens in a new tab)
Variant weakness
The product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated.
Implementation · Architecture and Design
Perform adequate input validation against any value that influences the amount of memory that is allocated. Define an appropriate strategy for handling requests that exceed the limit, and consider supporting a configuration option so that the administrator can extend the amount of memory to be used if necessary.
Operation
Run your program using system-provided resource limits for memory. This might still cause the program to crash or exit, but the impact to the rest of the system will be minimized.
OWASP Cheat Sheets
Abuse Case (opens in a new tab)
OWASP ASVS 4.0.3
V8.1.4 (opens in a new tab)
V13.4.1 (opens in a new tab)
V11.1.4 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

dnsdist.org/security-advisories/powerdns-advisory-for-dnsdist-2026-02.html (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 31 Mar 2026, 12:38 UTC

WeaknessesCWE-789

Technical details

References

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