Buffer overflow in Powerdns Dnsdist

CVE-2026-27853

An attacker might be able to trigger an out-of-bounds write by sending crafted DNS responses to a DNSdist using the DNSQuestion:changeName or DNSResponse:changeName methods in custom Lua code. In some cases the rewritten packet might become larger than the initial response and even exceed 65535 bytes, potentially leading to a crash resulting in denial of service.

Vulnerability class: Buffer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.015 (73.3th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 73rd percentile — 73.3% 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-2026-27853: rose from 0.005 to 0.015.

EPSS over last 30 days · oldest: 0.005 · newest: 0.015 · change: +0.010

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-27853?
CVE-2026-27853 is a medium-severity vulnerability in Powerdns Dnsdist, classified under Out-of-bounds Write. CVSS score: 5.9/10. Published 2026-03-31.
How severe is CVE-2026-27853?
Medium severity. CVSS v3 base score is 5.9 out of 10.