# CVE-2026-27854: dnsdist: An attacker might be able to trigger a use-after-free by sending crafted DNS queries to a DNSdist using the DNSQuesti...

CVE-2026-27854 is fixed in dnsdist on 1 platform, first by DEBIAN-CVE-2026-27854, released March 31, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-27854
- Priority: High
- CVSS: 7.5 (high)
- EPSS: 0.0049
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Mar 31, 2026

## Description

An attacker might be able to trigger a use-after-free by sending crafted DNS queries to a DNSdist using the DNSQuestion:getEDNSOptions method in custom Lua code. In some cases DNSQuestion:getEDNSOptions might refer to a version of the DNS packet that has been modified, thus triggering a use-after-free and potentially a crash resulting in denial of service.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | dnsdist Debian 13.5 (trixie) | 1.9.14-0+deb13u1 | [DEBIAN-CVE-2026-27854](https://patchblox.com/security/data/fix/linux/debian-cve-2026-27854.md) | Mar 31, 2026 |
| Linux | dnsdist Debian 14 | 2.0.3-1 | [DEBIAN-CVE-2026-27854](https://patchblox.com/security/data/fix/linux/debian-cve-2026-27854.md) | Mar 31, 2026 |
| Linux | dnsdist opensuse-leap 16.0 | 1.9.13-160000.1.1 | [OPENSUSE-SU-2026:21015-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21015-1.md) | Jun 22, 2026 |
| Linux | dnsdist sles 15.7 | 1.9.12-150700.3.9.1 | [SUSE-SU-2026:1618-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-1618-1.md) | Apr 24, 2026 |
| Linux | dnsdist sles 16.0 | 1.9.13-160000.1.1 | [SUSE-SU-2026:22319-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22319-1.md) | Jun 22, 2026 |

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Data as of 2026-11-09T07:25:28Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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