CVE catalog
CVE-2026-40211
An attacker can send crafted DNS over HTTP/3 queries, triggering an exception that prevents some buffer from being freed right away. The buffer will be freed at the end of the QUIC connection, but on
- 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 can send crafted DNS over HTTP/3 queries, triggering an exception that prevents some buffer from being freed right away. The buffer will be freed at the end of the QUIC connection, but on some setups it might be possible to open enough concurrent DoH3 streams to trigger an out-of-memory condition, resulting in a denial of service.
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-2026-40211]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-40211]
- [https://security-tracker.debian.org/tracker/CVE-2026-40211]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-40211.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]