Cyber Resilience

CVE-2026-33260

DoS in Powerdns Recursor 5.2.0 – 5.2.9

Published
22 April 2026
Modified
27 April 2026
Patch / advisory
CVSS Score v3.1 5.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
EPSS Score 0.0052 42th percentile
Risk Priority 45 floored blend · peak EPSS

Summary

CVE-2026-33260 is a medium-severity Allocation of Resources Without Limits or Throttling (CWE-770) vulnerability in Powerdns Recursor. Its CVSS base score is 5.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Network Denial of Service (T1498); ranked at the 42th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-10 (Concurrent Session Control) and SC-6 (Resource Availability) — 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-2026-33260 is a vulnerability in the internal web server of PowerDNS products, including PowerDNS Authoritative, PowerDNS Recursor, and dnsdist. It enables an attacker to send a specially crafted web request that triggers unlimited memory allocation, leading to denial of service via memory exhaustion. The internal web server is disabled by default, and the issue is classified under CWE-770 (Allocation of Resources Without Limits or Throttling), with a CVSS v3.1 base score of 5.3 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L).

The vulnerability can be exploited by any unauthenticated remote attacker with network access to the internal web server, requiring low attack complexity and no user interaction. Successful exploitation results in low-impact availability disruption through resource exhaustion, potentially causing the service to become unresponsive.

Security advisories published by PowerDNS detail mitigations and patches for the affected components: https://docs.powerdns.com/authoritative/security-advisories/powerdns-advisory-2026-05.html for Authoritative, https://docs.powerdns.com/recursor/security-advisories/powerdns-advisory-powerdns-2026-03.html for Recursor, and https://www.dnsdist.org/security-advisories/powerdns-advisory-for-dnsdist-2026-04.html for dnsdist. Practitioners should review these for version-specific updates and apply patches promptly, while ensuring the internal web server remains disabled unless required.

EU & UK References

Vulnerability Data

An attacker can send a web request that causes unlimited memory allocation in the internal web server, leading to a denial of service. The internal web server is disabled by default.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1498 Network Denial of Service Impact
Adversaries may perform Network Denial of Service (DoS) attacks to degrade or block the availability of targeted resources to users.
T1499 Endpoint Denial of Service Impact
Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users.
T1499.003 Application Exhaustion Flood Impact
Adversaries may target resource intensive features of applications to cause a denial of service (DoS), denying availability to those applications.
T1498.001 Direct Network Flood Impact
Adversaries may attempt to cause a denial of service (DoS) by directly sending a high-volume of network traffic to a target.
T1498.002 Reflection Amplification Impact
Adversaries may attempt to cause a denial of service (DoS) by reflecting a high-volume of network traffic to a target.
T1499.001 OS Exhaustion Flood Impact
Adversaries may launch a denial of service (DoS) attack targeting an endpoint's operating system (OS).
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-33257Same product: Powerdns Authoritative
CVE-2026-0398Same product: Powerdns Recursor
CVE-2026-33258Same product: Powerdns Recursor
CVE-2026-33254Same product: Powerdns Dnsdist
CVE-2026-33595Same product: Powerdns Dnsdist
CVE-2026-33256Same product: Powerdns Recursor
CVE-2026-33594Same product: Powerdns Dnsdist
CVE-2026-42001Same product: Powerdns Authoritative
CVE-2023-26437Same product: Powerdns Recursor
CVE-2026-33610Same product: Powerdns Authoritative

Affected Assets

powerdns
authoritative
4.9.0 — 4.9.14 · 5.0.0 — 5.0.4
powerdns
dnsdist
1.9.0 — 1.9.13 · 2.0.0 — 2.0.4
powerdns
recursor
5.4.0 · 5.2.0 — 5.2.9 · 5.3.0 — 5.3.6

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 5 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V15.4.4

Mitigating Controls (NIST 800-53 r5) AI

Directly enforces a hard limit on concurrent sessions, structurally preventing unbounded resource allocation.

Requires explicit allocation of resources by priority or quota, directly stopping unlimited allocation.

Imposes a limit on consecutive invalid attempts, preventing one specific class of unbounded resource consumption.

Reduces impact of resulting DoS events without preventing the underlying lack of allocation limits.

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.IR-04 mostly match
degrades

Monitoring capacity and taking action to maintain availability directly reduces unchecked resource allocation.

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.

finds

Baseline comparison of CPU, memory and bandwidth usage helps surface uncontrolled resource allocations before they cause service degradation.

prevents

Capacity projections and elasticity measures ensure that allocation requests are bounded and can be throttled, reducing the window in which an attacker can force unbounded resource reservations.

mitigates

Defining retention periods and deletion schedules for backup copies prevents indefinite accumulation of data on storage media without corresponding resource-management controls.

mitigates

Architectural redundancy and automatic failover limit the impact of an attacker who forces excessive allocations, because spare capacity can absorb the load until the primary instance recovers.

none

Documented incident response procedures that include activation of continuity plans and controlled recovery help ensure that resource consumption triggered by an incident is bounded and managed rather than left unbounded.

mitigates

Mandating tested continuity procedures that preserve or replace resource-limiting controls prevents an attacker from exploiting the absence of throttling mechanisms during an outage.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (2 rules)
  • V-248552 OL 8 must be configured so that all network connections associated with SSH traffic terminate after becoming unresponsive. prevents CWE-770
  • V-248553 OL 8 must be configured so that all network connections associated with SSH traffic are terminated after 10 minutes of becoming unresponsive. prevents CWE-770
Oracle Linux 9 (2 rules)
  • V-271710 OL 9 must be configured so that all network connections associated with SSH traffic are terminated after 10 minutes of becoming unresponsive. prevents CWE-770
  • V-271709 OL 9 must be configured so that all network connections associated with SSH traffic terminate after becoming unresponsive. prevents CWE-770
RHEL 8 (1 rule)
  • V-230244 RHEL 8 must be configured so that all network connections associated with SSH traffic terminate after becoming unresponsive. prevents CWE-770

References