NVD / CVE Program· CNA OX

CVE-2026-33254: Resource exhaustion via DoQ/DoH3 connections

Noroxi assessment

Priority: Monitor (action score 30/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.37% (FIRST EPSS).
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
According to CISA the attack is automatable: targets can be found by mass scanning.
Fixed version: PowerDNS DNSdist 1.9.13, 2.0.4.
Severity is disputed: the assigning authority (CNA) scores it 5.3, NVD 7.5.

Low priority for now. Upgrade to PowerDNS DNSdist 1.9.13, 2.0.4 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

An attacker can create a large number of concurrent DoQ or DoH3 connections, causing unlimited memory allocation in DNSdist and leading to a denial of service. DOQ and DoH3 are disabled by default.

HighCVSS 7.5 · v3.1—No exploit Fix available

Published: Apr 22, 2026
Updated: Oct 26, 2026
EPSS: 0.3% · 31th percentile
CWE: CWE-770

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 30 / 40 · 7.5 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.3%

CISA SSVC decision

Exploitation: none
Automatable: yes
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: 7.5
CNA · OX: 5.3; 2.2 point gap

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

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
powerdns	dnsdist	cpe:2.3:a:powerdns:dnsdist

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

powerdns dnsdist1.9.0 and later · before 1.9.13
powerdns dnsdist2.0.0 and later · before 2.0.4

Versions reported by the vendor

Affected version ranges reported by the assigning authority (OX). Independent of NVD's CPE analysis and usually ahead of it.

PowerDNS DNSdist
- 1.9.0 and later · before 1.9.13affected · semver
- 2.0.0 and later · before 2.0.4affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Alpine:v3.23	dnsdist	from 1.9.0 · before 2.0.4-r0	2.0.4-r0
Debian:12	dnsdist	from 0	—
Debian:13	dnsdist	before 1.9.14-0+deb13u1	1.9.14-0+deb13u1
Debian:14	dnsdist	before 2.0.4-1	2.0.4-1
openSUSE:Leap 16.0	dnsdist	before 1.9.13-160000.1.1	1.9.13-160000.1.1
openSUSE:Tumbleweed	dnsdist	before 2.0.5-1.1	2.0.5-1.1
SUSE:Linux Enterprise Server 16.0	dnsdist	before 1.9.13-160000.1.1	1.9.13-160000.1.1

Same product

powerdns: all records

Other highest-scoring records for the same primary product.

CVE-2026-33598Out-of-bounds read in cache inspection via Lua
36Monitor
CVE-2017-7557dnsdist version 1.1.0 is vulnerable to a flaw in authentication mechanism for REST API potentially allowing CSRF attack.
35Monitor
CVE-2026-33602Off-by-one access when processing crafted UDP responses
32Monitor

Published before and after this one in the same product

← EarlierCVE-2026-27853Mar 31, 2026 · Out-of-bounds write when rewriting large DNS packets
30Monitor
← EarlierCVE-2026-27854Mar 31, 2026 · Use after free when parsing EDNS options in Lua
30Monitor
Later →CVE-2026-33593Apr 22, 2026 · Denial of service via crafted DNSCrypt query
30Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
PowerDNS DNSdist	1.9.13	Vendor (CNA)
PowerDNS DNSdist	2.0.4	Vendor (CNA)
alpine:dnsdist	2.0.4-r0 · Alpine:v3.23	Package registry (OSV)
debian:dnsdist	1.9.14-0+deb13u1 · Debian:13	Package registry (OSV)
opensuse:dnsdist	2.0.5-1.1 · openSUSE:Tumbleweed	Package registry (OSV)
suse:dnsdist	1.9.13-160000.1.1 · SUSE:Linux Enterprise Server 16.0	Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Salvor Labs - https://salvor.frfinder

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

CVE-2026-335940 days apartOutgoing DoH excessive memory allocation
30Monitor
CVE-2026-335950 days apartDoQ/DoH3 excessive memory allocation
30Monitor
CVE-2026-4021164 days apartDenial of service via crafted DoH3 queries
21Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: none
Integrity: none
Availability: high · the service can be disrupted

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: None
Integrity impact: None
Availability impact: High

Weakness class (CWE)

CWE-770 · Allocation of Resources Without Limits or Throttling

CVSS vector

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

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

ATT&CK techniques

Change log

Fix✗ → ✓Sep 28, 2026, 10:10 PM UTC

For records you follow, these changes also arrive as notifications. →

References

www.dnsdist.org/security-advisories/powerdns-advisory-for-dnsdist-2026-04.html

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records