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CVE-2026-123572

Panic on a malformed `alpn` value when parsing SVCB or HTTPS records from text

Products / packages hickory-dns · hickory-proto

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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

The hickory-dns product, specifically versions before 0.26.2, is vulnerable to a denial of service when parsing SVCB or HTTPS records from untrusted text sources with malformed `alpn` values. The parser panics instead of returning an error. Records from DNS wire format are not affected.

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

0.20.1 → before 0.26.2

semver 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 0.20.1 before 0.26.2Semantic versions0.26.2

Version evidence: OSV · RUSTSEC-2026-0487

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 an SVCB or HTTPS record is parsed from its text (zone file) form, the alpn service parameter value is split into a list of protocol names. That step called expect on the result, on the assumption that it could not fail. A malformed value, such as one with an unbalanced quote (alpn="h), two commas in a row or an invalid escape, makes it fail, so the parser panicked instead of returning an error.

Code that parses zone files or record text from an untrusted source can be made to panic, which is a denial of service. Records decoded from the DNS wire format are not parsed this way.

The fix returns a parse error instead. It is in 0.26.2.

References

5 sources
hickory-dns/hickory-dns · security/advisories/GHSA-hx8c-fjhc-hmf5
Vendor advisoryVulnCheck
crates.io/crates/hickory-proto
Source reference
rustsec.org/advisories/RUSTSEC-2026-0487.html
Security advisory
hickory-dns/hickory-dns · commit 80eaf9e
Patch
www.vulncheck.com/advisories/hickory-dns-0.20.1-before-0.26.2-panic-dos-via-svcb-https-zone-parser
Security advisoryVulnCheck

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-2026-123572

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-1286 ↗

Improper Validation of Syntactic Correctness of Input

VulnCheck

Related →
Contributing organizations · 2
VulnCheck

Assigning organization

2026-11-08
CISA-ADP

Additional data publisher

2026-11-12

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-2026-123572

    Observed 2026-11-12T18:51:41.845Z · upstream updated 2026-11-12T17:51:02.771Z

    Prioritization updated

    before

    []

    after

    [
  {
    "source": "CISA-ADP",
    "type": "SSVC",
    "role": "CISA Coordinator",
    "timestamp": "2026-11-12T17:50:51.241591Z",
    "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.