CVE-2026-33602 PUBLISHED

Off-by-one access when processing crafted UDP responses

Assigner: OX
Reserved: 23.03.2026 Published: 22.04.2026 Updated: 22.04.2026

A rogue backend can send a crafted UDP response with a query ID off by one related to the maximum configured value, triggering an out-of-bounds write leading to a denial of service.

Metrics

CVSS 3.1

CVSS Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H
CVSS Score: 6.5

Attack Vector	Network	Scope	Unchanged
Attack Complexity	High	Confidentiality Impact	None
Privileges Required	None	Integrity Impact	Low
User Interaction	None	Availability Impact	High

CVSS 3.1

Product Status

Vendor	PowerDNS
Product	DNSdist
Versions	Default: unaffected affected from 1.9.0 to 1.9.13 (excl.) affected from 2.0.0 to 2.0.4 (excl.)

Credits

ylwango613 finder

References

https://www.dnsdist.org/security-advisories/powerdns-advisory-for-dnsdist-2026-04.html

Problem Types

Heap-based Buffer Overflow CWE