Description
Hickory DNS hickory-proto through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26.2 contain an NSEC validation flaw that returns a secure proof for NXDOMAIN responses when the covering NSEC's Next Domain Name is a strict descendant of the query name, which actually proves the name exists as an empty non-terminal. On-path attackers can flip the unsigned rcode of a genuine signed NODATA response from NOERROR to NXDOMAIN, causing validators to accept forged nonexistence of the name.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| hickory-dns | hickory-dns | ≤ 0.26.0-alpha.1, 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-net | 0.26.3-1 | — |
| Debian 14 | rust-hickory-proto | No fix yet | — |
| Debian 13 | rust-hickory-proto | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | rust-hickory-net +1 | No fix yet | — |
| Ubuntu 26.04 LTS | rust-hickory-proto | No fix yet | — |
| Ubuntu 24.04 LTS | rust-hickory-proto | No fix yet | — |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | netavark | No fix yet | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| crates.io | hickory-net | >= 0.0.0-0, < 0.26.2 | 0.26.2 | RUSTSEC-2026-0519 |
| crates.io | hickory-proto | >= 0.0.0-0, < 0.26.0-beta.1 | 0.26.0-beta.1 | RUSTSEC-2026-0511 |