Out-of-bounds Read in Powerdns Dnsdist

CVE-2026-33599

A rogue backend can send a crafted SVCB response to a Discovery of Designated Resolvers request, when requested via either the autoUpgrade (Lua) option to newServer or auto_upgrade (YAML) settings. DDR upgrade is not enabled by default.

Vulnerability class: Buffer Overflow

Published · last modified .

CVSS v3 metric

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

EPSS exploit prediction

EPSS: 0.008 (54.9th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 55th percentile — 54.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-33599: rose from 0.003 to 0.008.

EPSS over last 30 days · oldest: 0.003 · newest: 0.008 · change: +0.005

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-33599?
CVE-2026-33599 is a low-severity vulnerability in Powerdns Dnsdist, classified under Out-of-bounds Read. CVSS score: 3.1/10. Published 2026-04-22.
How severe is CVE-2026-33599?
Low severity. CVSS v3 base score is 3.1 out of 10.