# CVE-2018-16855: pdns-recursor: An issue has been found in PowerDNS Recursor before version 4.1.8 where aremote attacker sending a DNS query can trig...

CVE-2018-16855 is fixed in pdns-recursor on 1 platform, first by pdns-recursor 4.1.8-1, released January 16, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2018-16855
- Priority: Routine
- CVSS: n/a (Medium)
- EPSS: 0.5858
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no

## Description

An issue has been found in PowerDNS Recursor before version 4.1.8 where aremote attacker sending a DNS query can trigger an out-of-bounds memoryread while computing the hash of the query for a packet cache lookup,possibly leading to a crash.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | pdns-recursor Ubuntu 24.10 (oracular) | 4.1.8-1 | [pdns-recursor 4.1.8-1](https://patchblox.com/security/data/fix/linux/ubuntu-oracular-pdns-recursor-4.1.8-1.md) | Jan 16, 2026 |
| Linux | pdns-recursor Ubuntu 25.04 (plucky) | 4.1.8-1 | [pdns-recursor 4.1.8-1](https://patchblox.com/security/data/fix/linux/ubuntu-plucky-pdns-recursor-4.1.8-1.md) | Jan 16, 2026 |

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Data as of 2026-11-07T18:46:35Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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