What is CVE-2026-27854?

CVE-2026-27854 is a medium-severity vulnerability in Powerdns Dnsdist, classified under Use After Free. CVSS score: 4.8/10. Published 2026-03-31.

How severe is CVE-2026-27854?

Medium severity. CVSS v3 base score is 4.8 out of 10.

Use After Free in Powerdns Dnsdist

CVE-2026-27854

An attacker might be able to trigger a use-after-free by sending crafted DNS queries to a DNSdist using the DNSQuestion:getEDNSOptions method in custom Lua code. In some cases DNSQuestion:getEDNSOptions might refer to a version of the DNS packet that has been modified, thus triggering a use-after-free and potentially a crash resulting in denial of service.

Vulnerability class: Use-After-Free

EPSS: 0.005 (38.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L.

Affected products

Powerdns Dnsdist — versions 1.9.0, 2.0.0

Weakness classification (CWE)

CWE-416 — Use After Free

References

security@open-xchange.com (Vendor Advisory)

Frequently asked questions

What is CVE-2026-27854?: CVE-2026-27854 is a medium-severity vulnerability in Powerdns Dnsdist, classified under Use After Free. CVSS score: 4.8/10. Published 2026-03-31.
How severe is CVE-2026-27854?: Medium severity. CVSS v3 base score is 4.8 out of 10.