Description
If the auth responds very slowly and the records expire in between, the capping of TTLs is not enforced for lack of data. This does not happen on regular resolve as then then the
child records are used immediately if not expired and thus valid, or the
records are expired, and in that case not used. So this case
can only happen if almost expired records are used to refresh the
authoritative NS records.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| PowerDNS | Recursor | 0.0.0 – < 5.5.0 | 5.5.0 |
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 | pdns-recursor | No fix yet | — |
| Debian 13 | pdns-recursor | No fix yet | — |
| Debian 12 | pdns-recursor | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | pdns-recursor | No fix yet | — |
| Ubuntu 26.04 LTS | pdns-recursor | No fix yet | — |
| Ubuntu 24.04 LTS | pdns-recursor | No fix yet | — |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 22.04 LTS | pdns-recursor | No fix yet | — |
| Ubuntu Pro 20.04 LTS | pdns-recursor | No fix yet | — |
| Ubuntu Pro 18.04 LTS | pdns-recursor | No fix yet | — |
| Ubuntu Pro 16.04 LTS | pdns-recursor | No fix yet | — |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | pdns-recursor | 5.4.8-1.1 | openSUSE-SU-2026:12532-1 |
Advisories 1
- openSUSE-SU-2026:12532-1 pdns-recursor-5.4.8-1.1 on GA media SUSE / openSUSE Security Updates · Nov 12, 2026