What is CVE-2026-33259?

CVE-2026-33259 is a medium-severity vulnerability in Powerdns Recursor, classified under Use After Free. CVSS score: 5.0/10. Published 2026-04-22.

How severe is CVE-2026-33259?

Medium severity. CVSS v3 base score is 5.0 out of 10.

Use After Free in Powerdns Recursor

CVE-2026-33259

Having many concurrent transfers of the same RPZ can lead to inconsistent RPZ data, use after free and/or a crash of the recursor. Normally concurrent transfers of the same RPZ zone can only occur with a malfunctioning RPZ provider.

Vulnerability class: Use-After-Free

EPSS: 0.002 (13.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.0 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:L/A:H.

Affected products

Powerdns Recursor — versions 5.4.0, 5.3.0, 5.2.0

Weakness classification (CWE)

CWE-416 — Use After Free

References

security@open-xchange.com (Broken Link, Vendor Advisory)

Frequently asked questions

What is CVE-2026-33259?: CVE-2026-33259 is a medium-severity vulnerability in Powerdns Recursor, classified under Use After Free. CVSS score: 5.0/10. Published 2026-04-22.
How severe is CVE-2026-33259?: Medium severity. CVSS v3 base score is 5.0 out of 10.