Cyber Resilience

CVE-2026-33602

Memory Safety in Powerdns Dnsdist 1.9.0 – 1.9.13

Memory Safety
Published
22 April 2026
Modified
24 April 2026
Patch / advisory
View advisory
CVSS Score v3.1 6.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H
EPSS Score 0.0073 51th percentile
Risk Priority 51 floored blend · peak EPSS

Summary

CVE-2026-33602 is a medium-severity Heap-based Buffer Overflow (CWE-122) vulnerability in Powerdns Dnsdist. Its CVSS base score is 6.5 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 49% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-33602 affects dnsdist, the DNS load balancer from PowerDNS. The vulnerability is an out-of-bounds write (CWE-122) triggered when a rogue backend sends a crafted UDP response with a query ID off by one relative to the maximum configured value. Published on 2026-04-22, it carries a CVSS v3.1 base score of 6.5 (AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H), indicating medium severity with network accessibility, high attack complexity, no privileges required, no user interaction, unchanged scope, no confidentiality impact, low integrity impact, and high availability impact.

An attacker positioned as a rogue backend server that dnsdist queries can exploit this vulnerability remotely over the network. The high complexity arises from crafting the specific UDP response with the manipulated query ID. Exploitation results in an out-of-bounds write, leading to a denial of service, potentially crashing the dnsdist process and disrupting DNS resolution services.

The PowerDNS security advisory provides details on mitigation and patches; refer to https://www.dnsdist.org/security-advisories/powerdns-advisory-for-dnsdist-2026-04.html for guidance.

EU & UK References

Vulnerability Data

A rogue backend can send a crafted UDP response with a query ID off by one related to the maximum configured value, triggering an out-of-bounds write leading to a denial of service.

CWE(s)
CWE-122

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
attack.mitre.org →
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-27854Same product: Powerdns Dnsdist
CVE-2026-33599Same product: Powerdns Dnsdist
CVE-2026-33598Same product: Powerdns Dnsdist
CVE-2026-33596Same product: Powerdns Dnsdist
CVE-2026-27853Same product: Powerdns Dnsdist
CVE-2026-24029Same product: Powerdns Dnsdist
CVE-2026-33597Same product: Powerdns Dnsdist
CVE-2026-24028Same product: Powerdns Dnsdist
CVE-2026-0396Same product: Powerdns Dnsdist
CVE-2026-33593Same product: Powerdns Dnsdist

Affected Assets

powerdns
dnsdist
1.9.0 — 1.9.13 · 2.0.0 — 2.0.4

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V1.4.1

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation (including fuzzing and memory-error detectors) can discover heap overflows after they have been coded.

SI-10 Information Input Validation good match

Input validation enforces bounds checking on data written to heap buffers, directly stopping the overflow condition from being introduced.

SA-8 Security and Privacy Engineering Principles partial match

Security engineering principles require use of memory-safe constructs and bounds-checked allocation routines that avoid introducing heap overflows.

SI-16 Memory Protection partial match

Memory-protection mechanisms limit the ability of a heap overflow to execute attacker-controlled code or corrupt adjacent structures.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 full match
prevents

Secure-development practices directly require bounds checking and safe memory handling that prevent heap overflows.

ID.RA-01 partial match
prevents

Vulnerability scanning and recording can discover heap-overflow flaws but does not prevent their introduction in code.

PR.PS-02 partial match
prevents

Timely patching removes known heap-overflow instances after they exist.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing in development and acceptance can detect heap overflows before release.

A.8.25 Secure development life cycle partial match
prevents

Secure development lifecycle mandates practices that reduce the likelihood of introducing heap overflows.

A.8.26 Application security requirements partial match
prevents

Application security requirements can specify bounds-checking and safe memory APIs that mitigate heap overflows.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture and engineering principles include memory-safety and input-validation controls that address heap overflows.

A.8.28 Secure coding partial match
prevents

Secure coding standards directly prescribe techniques (safe functions, bounds checks) that prevent heap-based buffer overflows.

A.8.32 Change management none match
none

Change management ensures controlled deployment of fixes for discovered heap-overflow vulnerabilities.

References