Denial of service via crafted DoH3 queries
An attacker can send crafted DNS over HTTP/3 queries, triggering an exception that prevents some buffer from being freed right away. The buffer will be freed at the end of the QUIC connection, but on some setups it might be possible to open enough concurrent DoH3 streams to trigger an out-of-memory condition, resulting in a denial of service.
- Published
- Jun 25, 2026
- Updated
- Jun 25, 2026
- EPSS
- 0.7% · 51th percentile
- CWE
- CWE-770
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Report tools
Action score
21
Monitor
Low priority for now.
- CVSS
- 21 / 40 · 5.3 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.7%
CISA SSVC decision
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · OX
- 5.3
- NVD has not scored this yet; the score shown is the CNA’s.
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Affected systems
—
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 1.9.15affected · semver
- 2.0.0 and later · before 2.0.7affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | dnsdist | all versions | — |
| Debian:13 | dnsdist | before 1.9.15-0+deb13u1 | 1.9.15-0+deb13u1 |
| Debian:14 | dnsdist | before 2.1.0-1 | 2.1.0-1 |
| openSUSE:Leap 16.0 | dnsdist | before 1.9.15-160000.1.1 | 1.9.15-160000.1.1 |
| openSUSE:Tumbleweed | dnsdist | before 2.0.7-1.1 | 2.0.7-1.1 |
| SUSE:Linux Enterprise Server 16.0 | dnsdist | before 1.9.15-160000.1.1 | 1.9.15-160000.1.1 |
Same product
powerdns: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-33598Out-of-bounds read in cache inspection via Lua37Monitor
- 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 responses32Monitor
- CVE-2026-33599Out-of-bounds read in service discovery32Monitor
- CVE-2026-24028Out-of-bounds read when parsing DNS packets via Lua32Monitor
- CVE-2025-30194Denial of service via crafted DoH exchange31Monitor
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 | 1.9.15 | Vendor (CNA) |
| PowerDNS DNSdist | 2.0.7 | Vendor (CNA) |
| debian:dnsdist | 1.9.15-0+deb13u1 · Debian:13 | Package registry (OSV) |
| opensuse:dnsdist | 2.0.7-1.1 · openSUSE:Tumbleweed | Package registry (OSV) |
| suse:dnsdist | 1.9.15-160000.1.1 · 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.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
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 researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
- Mehtab Zafarfinder
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2026-3325464 days apartResource exhaustion via DoQ/DoH3 connections30Monitor
- CVE-2026-3359464 days apartOutgoing DoH excessive memory allocation30Monitor
- CVE-2026-3359564 days apartDoQ/DoH3 excessive memory allocation30Monitor
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
- low · 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
- Low
Weakness class (CWE)
CWE-770 · Allocation of Resources Without Limits or ThrottlingCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
nvd-secondary
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)
- FloodingCAPEC-125likelihood: High · Medium
- Excessive AllocationCAPEC-130likelihood: Medium · Medium
- XML Ping of the DeathCAPEC-147likelihood: Low · Medium
- Exponential Data ExpansionCAPEC-197likelihood: High · Medium
- Serialized Data Parameter BlowupCAPEC-229likelihood: High · High
- Serialized Data with Nested PayloadsCAPEC-230likelihood: Medium · High
- Oversized Serialized Data PayloadsCAPEC-231likelihood: Medium · High
- HTTP DoSCAPEC-469Low
ATT&CK techniques
- Network Denial of Service:Direct Network FloodT1498.001
- Network Denial of Service:Reflection AmplificationT1498.002
- Endpoint Denial of ServiceT1499
- Endpoint Denial of Service: OS Exhaustion FloodT1499.001
- Endpoint Denial of Service:Service Exhaustion FloodT1499.002
- Endpoint Denial of Service:Application Exhaustion FloodT1499.003
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
- Fix✗ → ✓
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References
Vendor advisories and official records. Exploit/PoC links are deliberately left out.