CVE catalog
CVE-2023-26249
knot-resolver: CVE-2023-26249
- Severity
- Medium
- Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.71% · Oct 25, 2026
Knot Resolver before 5.6.0 enables attackers to consume its resources, launching amplification attacks and potentially causing a denial of service. Specifically, a single client query may lead to a hundred TCP connection attempts if a DNS server closes connections without providing a response.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | knot-resolver | sid | 6.5.0-2 | fixed |
| Debian | knot-resolver | forky | 6.4.2-1 | fixed |
| Debian | knot-resolver | trixie | 5.7.5-1 | fixed |
| Debian | knot-resolver | bookworm | 5.6.0-1+deb12u1 | fixed |
| Debian | knot-resolver | bookworm-security | 5.6.0-1+deb12u1 | fixed |
| Ubuntu | knot-resolver | pro | 5.3.1-1 | vulnerable |
| Ubuntu | knot-resolver | pro | 5.4.2-1 | vulnerable |
| Ubuntu | knot-resolver | pro | 5.4.3-1 | vulnerable |
| Ubuntu | knot-resolver | pro | 5.4.4-1 | vulnerable |
| Ubuntu | knot-resolver | pro | 5.4.4-1ubuntu0.1~esm1 | vulnerable |
| Ubuntu | knot-resolver | 20.04 | 3.2.1-3 | vulnerable |
| Ubuntu | knot-resolver | 20.04 | 3.2.1-3ubuntu1 | vulnerable |
| Ubuntu | knot-resolver | 20.04 | 3.2.1-3ubuntu2 | vulnerable |
| Ubuntu | knot-resolver | 20.04 | 3.2.1-3ubuntu2.1 | vulnerable |
| Ubuntu | knot-resolver | 20.04 | 3.2.1-3ubuntu2.2 | vulnerable |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | knot-resolver | source | sid | 5.6.0-1 | not yet assigned | Not reported | Not reported |
| Debian | knot-resolver | source | forky | 5.6.0-1 | not yet assigned | Not reported | Not reported |
| Debian | knot-resolver | source | trixie | 5.6.0-1 | not yet assigned | Not reported | Not reported |
| Debian | knot-resolver | source | bookworm | 5.6.0-1 | not yet assigned | Not reported | Not reported |
OpenFactory catalog packages
Matching against OpenFactory catalog package versions is in progress.