# CVE-2026-123570: rust-hickory-proto: The DNS wire-format message parser in hickory-proto (Hickory DNS) 0.18 before 0.26.2 preallocates record vectors size...

CVE-2026-123570 is fixed in rust-hickory-proto on 1 platform by DEBIAN-CVE-2026-123570 (version 0.26.3-1), released November 9, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-123570
- Priority: Routine
- CVSS: n/a
- EPSS: 0.0041
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Nov 8, 2026

## Description

The DNS wire-format message parser in hickory-proto (Hickory DNS) 0.18 before 0.26.2 preallocates record vectors sized by the untrusted ANCOUNT, NSCOUNT, and ARCOUNT header fields before reading record data. Remote attackers can send a UDP datagram, or a spoofed response to a client/resolver, with these counts set to 65535, forcing about 18MB of allocation per message.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | rust-hickory-proto Debian 14 | 0.26.3-1 | [DEBIAN-CVE-2026-123570](https://patchblox.com/security/data/fix/linux/debian-cve-2026-123570.md) | Nov 9, 2026 |

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Data as of 2026-11-11T01:43:54Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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