Vulnerability in Hickory-Dns
CVE-2026-123572
Hickory-dns from 0.20.1 before 0.26.2 contains a denial of service vulnerability in the hickory-proto SVCB and HTTPS record presentation format parser, which panics on malformed alpn values. Attackers can supply untrusted zone files with unbalanced quotes, consecutive commas, or invalid escapes in alpn parameters to crash parsing processes.
Published .
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: 0.003 (28.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 28th percentile — 28.1% 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
Weakness classification (CWE)
References
- github.com/hickory-dns/hickory-dns/security/advisories/GHSA-hx8c-fjhc-hmf5 (vendor-advisory)
- www.vulncheck.com/advisories/hickory-dns-0.20.1-before-0.26.2-panic-dos-via-svc… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-123572?
- CVE-2026-123572 is a high-severity vulnerability in Hickory-Dns, classified under CWE-1286. CVSS score: 7.5/10. Published 2026-11-08.
- How severe is CVE-2026-123572?
- High severity. CVSS v3 base score is 7.5 out of 10.