What is CVE-2026-123576?

CVE-2026-123576 is a high-severity vulnerability in Hickory-Dns, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 7.5/10. Published 2026-11-08.

How severe is CVE-2026-123576?

High severity. CVSS v3 base score is 7.5 out of 10.

Resource exhaustion in Hickory-Dns

CVE-2026-123576

Hickory DNS 0.24.0 through 0.26.1 contains a memory exhaustion vulnerability that allows remote attackers to consume server resources by sending incomplete DNS-over-QUIC request bodies. Attackers can open many connections and send only large length prefixes, causing pre-allocated buffers to persist without timeout and exhausting server memory.

Published 2026-11-08.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.004 (35.5th percentile), scored 2026-11-09.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 35th percentile — 35.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

The 30-day trend appears once there are two daily scores.

Affected products

Hickory-Dns

Weakness classification (CWE)

CWE-770 — Allocation of Resources Without Limits or Throttling

References

github.com/hickory-dns/hickory-dns/security/advisories/GHSA-2f4m-fq7w-mrgx (vendor-advisory)
www.vulncheck.com/advisories/hickory-dns-0.24.0-through-0.26.1-memory-exhaustio… (third-party-advisory)

Frequently asked questions

What is CVE-2026-123576?: CVE-2026-123576 is a high-severity vulnerability in Hickory-Dns, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 7.5/10. Published 2026-11-08.
How severe is CVE-2026-123576?: High severity. CVSS v3 base score is 7.5 out of 10.