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CVE-2026-123570

Hickory DNS from 0.18 before 0.26.2 Memory Amplification DoS via RR Counts

Products / packages hickory-dns · hickory-proto

Published

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Severity and exploitation

Not in CISA KEV

KEV coverage does not rule out exploitation.

KEV checked 15/11/2026, 01:25:32 UTC
VulnCheck · CVSS:4.0 · 8.7
Assessment vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
VulnCheck · CVSS:3.1 · 7.5
Assessment vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
The headline uses the highest imported catalog score. Assessments can differ by source and CVSS version.

Severity

high8.7

CVSS measures technical severity, not the likelihood of an attack.

Known exploitation

Not listed in the checked CISA KEV catalog

Absence from CISA KEV does not rule out attacks.

Public exploit

Not established by this record

Missing evidence does not mean no public exploit exists.

Remediation

Package fixes recorded

Fix versions are recorded for 1 of 1 mapped packages. Check each release branch and any separate product guidance.

What this means

Hickory DNS versions 0.18 before 0.26.2 are vulnerable to a memory amplification denial-of-service (DoS) via RR counts. An attacker with access to send DNS messages can cause memory consumption. The weakness is uncontrolled resource consumption.

Summarized by @cf/meta/llama-3.3-70b-instruct-fp8-fast. Verify details against the original sources.

Attack conditions

No attack-condition excerpt has been identified here. Review the full source description and references for authentication, network access, and configuration requirements.

Review supporting sources →

Affected versions

Check the exact model, release, and any platform requirements against your installation.

hickory-dns · VulnCheck

hickory-dns

2 ranges
VulnCheck version evidence

Package identity

pkg:cargo/hickory-protoExplore hickory-proto →

Identity supplied by VulnCheck. Version matching requires compatible range evidence.

Compare with this publisher’s ranges. This does not inspect your installation.

affected

0.18 → before 0.26.2

custom versions

unaffected

0.26.2

semver versions

unknown

Other versions: unaffected

Packages

Compare each installed version with the publisher’s affected ranges. Where a fix is recorded, choose the appropriate release branch and test compatibility before upgrading.

hickory-proto crates.io
Affected range Recorded fix
From 0.18.0 before 0.26.2Semantic versions0.26.2

Version evidence: OSV · RUSTSEC-2026-0491

View original version evidence (0 explicit versions)

What to do

Compare your installed product and version with the affected versions above. A matching product name alone does not confirm exposure.

Use the recorded fix for your release branch. Review the publisher’s instructions and test compatibility before upgrading.

cve.new guidance unless attributed to a publisher. This page does not inspect your installation.

Public exploit evidence

No public exploit reference is identified in the imported evidence. This is not a claim that no exploit exists.

Original source description

Read the full publisher description

When a DNS message is decoded, the vectors for the question, answer, authority and additional sections were created with Vec::with_capacity set to the counts in the message header. Those counts come from the sender and are not checked against the size of the message, so a single small packet that claims 65,535 records makes the decoder reserve memory for that many records (about 18 MB, according to the upstream advisory) before it reads any record and fails.

Any code that decodes untrusted DNS messages is exposed. That includes servers, and clients and resolvers that receive spoofed responses. Repeated packets can drive memory use up and cause a denial of service.

The fix caps the initial capacity at 8 entries and lets the vectors grow as records are actually decoded. It is in 0.26.2.

References

5 sources
hickory-dns/hickory-dns · security/advisories/GHSA-67wc-6jq8-ghrc
Vendor advisoryVulnCheck
www.vulncheck.com/advisories/hickory-dns-from-0.18-before-0.26.2-memory-amplification-dos-via-rr-counts
Security advisoryVulnCheck
crates.io/crates/hickory-proto
Source reference
rustsec.org/advisories/RUSTSEC-2026-0491.html
Security advisory
hickory-dns/hickory-dns · commit 280c0e5
Patch

Inside the record

Evidence available

Package identity
Version evidence
Remediation guidance · not supplied
Weakness classification
Additional publishers

Describes the evidence in this view, not whether the product is safe.

Original records

CVE-2026-123570

View the latest unmodified CVE JSON from the official source. It may be newer than this imported page.

cve.new JSON →

Underlying weaknesses

The source’s classification of what caused the vulnerability.

CWE-400 ↗

Uncontrolled Resource Consumption

VulnCheck

Related →
Contributing organizations · 2
VulnCheck

Assigning organization

2026-11-08
CISA-ADP

Additional data publisher

2026-11-09

Timeline

All times UTC

  1. Advisory published

    Publication date supplied by the source.

  2. Source updated

    Latest modification date supplied by the source.

  3. Last imported by cve.new

    Latest catalog import, not the date we first saw this advisory.

What changed

Follow changes
  1. CVE · CVE-2026-123570

    Observed 2026-11-09T14:00:44.392Z · upstream updated 2026-11-09T13:55:57.344Z

    Prioritization updated

    before

    []

    after

    [
  {
    "source": "CISA-ADP",
    "type": "SSVC",
    "role": "CISA Coordinator",
    "timestamp": "2026-11-09T13:55:49.382736Z",
    "decisions": [
      {
        "name": "Exploitation",
        "value": "none"
      },
      {
        "name": "Automatable",
        "value": "yes"
      },
      {
        "name": "Technical Impact",
        "value": "partial"
      }
    ]
  }
]

Large field values are marked as truncated previews. Original source snapshots remain retained.

Showing up to 50 most recent observed changes.