Description
Hickory DNS hickory-resolver 0.26.0-beta.1 before 0.26.2 contains an unbounded retry loop in NameServerPool::try_send, which re-queues truncated (TC) responses without checking the answering transport or counting iterations. A malicious authoritative server returning TC=1 on every transport keeps the resolver spinning on a persistent TCP connection until the 5-second request deadline expires, causing resource exhaustion.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| hickory-dns | hickory-dns | 0.26.0-beta.1 – < 0.26.2 | 0.26.2 |
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 | rust-hickory-resolver | 0.26.3-1 | — |
| Debian 13 | rust-hickory-resolver | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | rust-hickory-resolver | No fix yet | — |
| Ubuntu 26.04 LTS | rust-hickory-resolver | No fix yet | — |
| Ubuntu 24.04 LTS | rust-hickory-resolver | No fix yet | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| crates.io | hickory-resolver | >= 0.26.0-beta.1, < 0.26.2 | 0.26.2 | GHSA-6w6g-hm98-mhgm |