CVE.org (no NVD analysis yet)· CNA VulnCheck

CVE-2026-123570: Hickory DNS from 0.18 before 0.26.2 Memory Amplification DoS via RR Counts

HighCVSS 8.7 · v4.0—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 34/100)

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: 0.40% (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: azl3 netavark 1.10.3-9 on Azure Linux 3.0 Release Notes.

Low priority for now. Upgrade to azl3 netavark 1.10.3-9 on Azure Linux 3.0 Release Notes 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

The DNS wire-format message parser in hickory-proto (Hickory DNS) 0.18 before 0.26.2 preallocates record vectors sized by the untrusted ANCOUNT, NSCOUNT, and ARCOUNT header fields before reading record data. Remote attackers can send a UDP datagram, or a spoofed response to a client/resolver, with these counts set to 65535, forcing about 18MB of allocation per message.

EUVD-2026-119455

Published: Nov 8, 2026
Updated: Nov 10, 2026
EPSS: 0.4% · 35th percentile
CWE: CWE-400

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 34 / 40 · 8.7 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.4%

CISA SSVC decision

Exploitation: none
Automatable: yes
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · VulnCheck: 8.7; NVD has not scored this yet; the score shown is the CNA’s.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

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.

Is your version affected? Check it

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.

—

Versions reported by the vendor

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

hickory-dns hickory-dns
- 0.26.2not affected
- 0.18 and later · before 0.26.2affected

Package-level exposure

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

Ecosystem	Package	Affected range	Fix
Debian:13	rust-hickory-proto	from 0	—
Debian:14	rust-hickory-proto	before 0.26.3-1	0.26.3-1

Same product

hickory-dns: all records

Other highest-scoring records for the same primary product.

CVE-2026-123587Hickory-DNS 0.26.0 before 0.26.2 DNSSEC Nonexistence Forgery via Wraparound NSEC
35Monitor
CVE-2026-123608Hickory DNS hickory-proto 0.3.1 before 0.26.1 CPU Exhaustion via BinEncoder Name Compression
34Monitor
CVE-2026-123607Hickory DNS NSEC3 Closest-Encloser Proof Unbounded Loop Denial of Service
34Monitor

Published before and after this one in the same product

← EarlierCVE-2025-25188Feb 10, 2025 · DNSSEC validation may accept broken authentication chains
22Monitor
Later →CVE-2026-123571Nov 8, 2026 · Hickory DNS from 0.26.0 before 0.26.2 Panic via TSIG RDATA Decoding
34Monitor
Later →CVE-2026-123572Nov 8, 2026 · Hickory-dns 0.20.1 before 0.26.2 Panic DoS via SVCB/HTTPS Zone Parser
34Monitor

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
azl3 netavark 1.10.3-9 on Azure Linux 3.0	Release Notes	Microsoft (MSRC)
debian:rust-hickory-proto	0.26.3-1 · Debian:14	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.

PublishedNov 8, 2026
Fix recordedNov 9, 2026+1 d
TodayNov 12, 2026+5 d

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Credits

All researchers

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

jpdsreporter

Variant candidates

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

CVE-2026-1235860 days apartHickory DNS 0.25.0-alpha.3 through 0.25.2 Query Amplification via Cyclic Referrals
34Monitor
CVE-2026-1236060 days apartHickory-DNS Recursor 0.25.0-alpha.3 through 0.25.2 Glueless-NS Referral Amplification
34Monitor
CVE-2026-1235850 days apartHickory DNS 0.25.0 before 0.26.2 Query Amplification via Irrelevant CNAME Records
27Monitor
CVE-2026-1235890 days apartHickory DNS before 0.26.2 Denial of Service via Missing DNS-over-QUIC Request Read Timeout
27Monitor

Not on record for this CVE: patch commit or PR link · public bounty program.

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
Integrity
Availability

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: X

Weakness class (CWE)

CWE-400 · Uncontrolled Resource Consumption

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

nvd-secondary

Root cause

Code that parses nested structures sets no depth or size limit. A small input can turn into a disproportionate processing load.

The bug in code

The whole CWE-400 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1function expand(node) {
2  return node.children.map(expand);
3}

Fixed

1const MAX_DEPTH = 32;
2function expand(node, depth = 0) {
3  if (depth > MAX_DEPTH) throw new Error("too deep");
4  return node.children.map((c) => expand(c, depth + 1));
5}

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

Endpoint Denial of ServiceT1499

Change log

SSVC exploitation— → noneNov 9, 2026, 3:07 PM UTC
Fix✗ → ✓Nov 9, 2026, 3:42 AM UTC
Exploit maturity— → noneNov 8, 2026, 3:07 AM UTC

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

References

github.com/hickory-dns/hickory-dns/security/advisories/GHSA-67wc-6jq8-ghrc

Show all references (1 more)

www.vulncheck.com/advisories/hickory-dns-from-0.18-before-0.26.2-memory-amplification-dos-via-rr-counts

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

All records