Description
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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| PowerDNS | DNSdist | 1.9.0 – < 1.9.15, 2.0.0 – < 2.0.7 | 1.9.15 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | dnsdist | 2.1.0-1 | — |
| Debian 13 | dnsdist | 1.9.15-0+deb13u1 | — |
| Debian 12 | dnsdist | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | dnsdist | No fix yet | — |
| Ubuntu 26.04 LTS | dnsdist | No fix yet | — |
| Ubuntu 25.10 | dnsdist | No fix yet | — |
| Ubuntu 16.04 LTS | dnsdist | No fix yet | — |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 24.04 LTS | dnsdist | No fix yet | — |
| Ubuntu Pro 22.04 LTS | dnsdist | No fix yet | — |
| Ubuntu Pro 20.04 LTS | dnsdist | No fix yet | — |
| Ubuntu Pro 18.04 LTS | dnsdist | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | dnsdist | 1.9.15-160000.1.1 | SUSE-SU-2026:23146-1, SUSE-SU-2026:23123-1 |
| SLES 16.0 | dnsdist | 1.9.15-160000.1.1 | SUSE-SU-2026:23146-1, SUSE-SU-2026:23123-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | dnsdist | 2.0.7-1.1 | openSUSE-SU-2026:11411-1 |
| openSUSE Leap 16.0 | dnsdist | 1.9.15-160000.1.1 | openSUSE-SU-2026:21533-1 |
Advisories 5
- WID-SEC-2026-2091 PowerDNS: Mehrere Schwachstellen BSI CERT-Bund (WID) · Aug 16, 2026
- SUSE-SU-2026:23146-1 Security update for dnsdist SUSE / openSUSE Security Updates · Aug 14, 2026
- SUSE-SU-2026:23123-1 Security update for dnsdist SUSE / openSUSE Security Updates · Aug 14, 2026
- openSUSE-SU-2026:21533-1 Security update for dnsdist SUSE / openSUSE Security Updates · Aug 6, 2026
- openSUSE-SU-2026:11411-1 dnsdist-2.0.7-1.1 on GA media SUSE / openSUSE Security Updates · Aug 1, 2026