How severe is CVE-2026-123574?

No CVSS score has been assigned to CVE-2026-123574 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-123574?

Affected package information for CVE-2026-123574 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2026-123574?

Upgrade the affected component to the fixed release for CVE-2026-123574, or apply your distribution's backported patch — distro builds are often patched at an older version number, so check your vendor's advisory rather than the upstream version alone.

How do I detect CVE-2026-123574 in my code and dependencies?

Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).

How do I mitigate CVE-2026-123574 if there is no patch (or I can't update yet)?

Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Is CVE-2026-123574 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-123574 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-123574?

CVE-2026-123574 has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 28th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-123574?

CVE-2026-123574 is classified as Improper Input Validation (CWE-20). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-123574 published, and has it been updated?

CVE-2026-123574 was published on November 8, 2026 and was last updated on November 8, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

Not in CISA KEV

CVE-2026-123574 — hickory-dns

CVE-2026-123574 is a Improper Input Validation vulnerability. A fix is available — see the affected versions and patch details below.

Hickory DNS 0.24.0 before 0.26.2 Denial of Service via Zone File Parser

Also known asGHSA-4rph-pmrw-mwpw

Published

Nov 8, 2026

Updated

Nov 8, 2026

Affected

16 versions

Patched

See advisory

Exploits

None indexed

Exploitation data as of Nov 8, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs28th percentile — riskier than 28% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Description

The zone file parser in the hickory-proto crate of Hickory DNS 0.24.0 before 0.26.2 panics when a single token in a zone file is 4096 bytes or longer. Attackers who can supply untrusted zone files to an application using the parser can trigger the panic to cause a denial of service.

Detection & mitigation playbook

Vulnerability

Detect
Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).
Fix
Upgrade the affected component to the fixed release for CVE-2026-123574, or apply your distribution's backported patch — distro builds are often patched at an older version number, so check your vendor's advisory rather than the upstream version alone.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Frequently Asked Questions

O3 Security · Impact-Aware SCA

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