Vulnerability · Published Apr 22, 2026 · Assigned by OX
CVE-2026-33602Off-by-one access when processing crafted UDP responses
Medium 6.5
In plain English
A medium-severity heap buffer overflow in DNSdist from PowerDNS. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 54% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)6.5Medium
Exploit odds (30 days)0.7%top 45.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.23 | dnsdist | 2.0.4-r0 | ALPINE-CVE-2026-33602 |
| Alpine:v3.24 | dnsdist | 2.0.4-r0 | ALPINE-CVE-2026-33602 |
| Debian:12 | dnsdist | no fix listed | DEBIAN-CVE-2026-33602 |
| Debian:13 | dnsdist | 1.9.14-0+deb13u1 | DEBIAN-CVE-2026-33602 |
| Debian:14 | dnsdist | 2.0.4-1 | DEBIAN-CVE-2026-33602 |
| Ubuntu:25.10 | dnsdist | no fix listed | UBUNTU-CVE-2026-33602 |
| Ubuntu:26.04:LTS | dnsdist | no fix listed | UBUNTU-CVE-2026-33602 |
| Ubuntu:26.10 | dnsdist | no fix listed | UBUNTU-CVE-2026-33602 |
Affected products (as reported)
Weakness: CWE-122 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H