CVE catalog
CVE-2026-40209
An attacker might be able to cause outgoing TCP connections to backend to be stuck until a timeout occurs instead of being released immediately, by sending IXFR queries. This could be used to cause a
- Severity
- High · CVSS 7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.70% · Oct 25, 2026
An attacker might be able to cause outgoing TCP connections to backend to be stuck until a timeout occurs instead of being released immediately, by sending IXFR queries. This could be used to cause a denial of service if there is a limit to the number of concurrent connections to this backend, or if the process runs out of file descriptors.
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 | dnsdist | sid | 2.1.3-1 | fixed |
| Debian | dnsdist | forky | 2.1.3-1 | fixed |
| Debian | dnsdist | trixie | 1.9.16-0+deb13u1 | fixed |
| Debian | dnsdist | trixie-security | 1.9.16-0+deb13u1 | fixed |
| Debian | dnsdist | bookworm | 1.7.3-2 | vulnerable |
| Cpe | dnsdist | Not reported | Not reported | vulnerable |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | dnsdist | source | sid | 2.1.0-1 | not yet assigned | Not reported | Not reported |
| Debian | dnsdist | source | forky | 2.1.0-1 | not yet assigned | Not reported | Not reported |
| Debian | dnsdist | source | trixie | 1.9.15-0+deb13u1 | not yet assigned | Not reported | Not reported |
| Debian | dnsdist | source | bookworm | (unfixed) | end-of-life | Not reported | Not reported |
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [dnsdist]Affected
Details (2)
1.7.3-2· amd64 · bookwormAffected
nvd · dnsdist · debian · bookworm; nvd · dnsdist · debian · 12
1.7.3-2· arm64 · bookwormAffected
nvd · dnsdist · debian · bookworm; nvd · dnsdist · debian · 12
[Debian 13 (Trixie)]
- [dnsdist]Fixed
Details (4)
1.9.15-0+deb13u1· amd64 · trixieFixed · Fixed:
1.9.15-0+deb13u1nvd · dnsdist · debian · 13
1.9.15-0+deb13u1· arm64 · trixieFixed · Fixed:
1.9.15-0+deb13u1nvd · dnsdist · debian · 13
1.9.16-0+deb13u1· amd64 · trixie-securityFixed · Fixed:
1.9.15-0+deb13u1nvd · dnsdist · debian · 13
1.9.16-0+deb13u1· arm64 · trixie-securityFixed · Fixed:
1.9.15-0+deb13u1nvd · dnsdist · debian · 13
Observed:
References
- [https://ftp.suse.com/pub/projects/security/csaf/opensuse-su-2026_11411-1.json]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-40209]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-40209]
- [https://security-tracker.debian.org/tracker/CVE-2026-40209]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-40209.json]
- [https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-2091.json]
- [https://www.dnsdist.org/security-advisories/powerdns-advisory-for-dnsdist-2026-09.html]
[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]