# CVE-2026-32792: Packet of death with DNSCrypt

CVE-2026-32792 is fixed in 5 products on 1 platform, first by libunbound8 1.24.2-1ubuntu2.1, released May 19, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-32792
- Priority: Routine
- CVSS: 5.3 (Moderate)
- EPSS: 0.0034
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: May 19, 2026
- Weakness: Improper Handling of Missing Special Element
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-32792

## Description

NLnet Labs Unbound 1.6.2 up to and including version 1.25.0 has a denial of service vulnerability when compiled with DNSCrypt support ('--enable-dnscrypt'). A bad DNSCrypt query could underflow Unbound's DNSCrypt packet reading procedure that may lead to heap overflow. A malicious actor can exploit the vulnerability with a single bad DNSCrypt query that its decrypted plaintext consists entirely of '0x00' bytes and does not contain the expected '0x80' marker. Unbound would then start reading more bytes than necessary until it finds a non-'0x00' byte. Based on the underlying memory allocator and the memory layout, it could lead to heap overflow while reading followed by a crash. Likelihood of a crash is low, since it relies heavily on the underlying memory allocator and the memory layout. If the heap overflow does not happen, Unbound's later packet checks will deny the packet. Unbound 1.25.1 contains a patch with a fix to bound reading in the given buffer space.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | libunbound8 Ubuntu 22.04.1 LTS (jammy) | 1.13.1-1ubuntu5.15 | [libunbound8 1.13.1-1ubuntu5.15](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-libunbound8-1.13.1-1ubuntu5.15.md) | May 27, 2026 |
| Linux | libunbound8 Ubuntu 24.04.5 LTS (noble) | 1.19.2-1ubuntu3.8 | [libunbound8 1.19.2-1ubuntu3.8](https://patchblox.com/security/data/fix/linux/ubuntu-noble-libunbound8-1.19.2-1ubuntu3.8.md) | May 27, 2026 |
| Linux | libunbound8 Ubuntu 25.10 (questing) | 1.22.0-2ubuntu2.3 | [libunbound8 1.22.0-2ubuntu2.3](https://patchblox.com/security/data/fix/linux/ubuntu-questing-libunbound8-1.22.0-2ubuntu2.3.md) | May 27, 2026 |
| Linux | libunbound8 Ubuntu 26.04.1 LTS (resolute) | 1.24.2-1ubuntu2.1 | [libunbound8 1.24.2-1ubuntu2.1](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-libunbound8-1.24.2-1ubuntu2.1.md) | May 19, 2026 |
| Linux | python3-unbound Ubuntu 22.04.1 LTS (jammy) | 1.13.1-1ubuntu5.15 | [python3-unbound 1.13.1-1ubuntu5.15](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-python3-unbound-1.13.1-1ubuntu5.15.md) | May 27, 2026 |
| Linux | python3-unbound Ubuntu 24.04.5 LTS (noble) | 1.19.2-1ubuntu3.8 | [python3-unbound 1.19.2-1ubuntu3.8](https://patchblox.com/security/data/fix/linux/ubuntu-noble-python3-unbound-1.19.2-1ubuntu3.8.md) | May 27, 2026 |
| Linux | python3-unbound Ubuntu 25.10 (questing) | 1.22.0-2ubuntu2.3 | [python3-unbound 1.22.0-2ubuntu2.3](https://patchblox.com/security/data/fix/linux/ubuntu-questing-python3-unbound-1.22.0-2ubuntu2.3.md) | May 27, 2026 |
| Linux | python3-unbound Ubuntu 26.04.1 LTS (resolute) | 1.24.2-1ubuntu2.1 | [python3-unbound 1.24.2-1ubuntu2.1](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-python3-unbound-1.24.2-1ubuntu2.1.md) | May 19, 2026 |
| Linux | unbound Debian 13.5 (trixie) | 1.22.0-2+deb13u3 | [DEBIAN-CVE-2026-32792](https://patchblox.com/security/data/fix/linux/debian-cve-2026-32792.md) | May 27, 2026 |
| Linux | unbound Debian 14 | 1.25.1-1 | [DEBIAN-CVE-2026-32792](https://patchblox.com/security/data/fix/linux/debian-cve-2026-32792.md) | May 27, 2026 |
| Linux | unbound Ubuntu 22.04.1 LTS (jammy) | 1.13.1-1ubuntu5.15 | [unbound 1.13.1-1ubuntu5.15](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-unbound-1.13.1-1ubuntu5.15.md) | May 27, 2026 |
| Linux | unbound Ubuntu 24.04.5 LTS (noble) | 1.19.2-1ubuntu3.8 | [unbound 1.19.2-1ubuntu3.8](https://patchblox.com/security/data/fix/linux/ubuntu-noble-unbound-1.19.2-1ubuntu3.8.md) | May 27, 2026 |
| Linux | unbound Ubuntu 25.10 (questing) | 1.22.0-2ubuntu2.3 | [unbound 1.22.0-2ubuntu2.3](https://patchblox.com/security/data/fix/linux/ubuntu-questing-unbound-1.22.0-2ubuntu2.3.md) | May 27, 2026 |
| Linux | unbound Ubuntu 26.04.1 LTS (resolute) | 1.24.2-1ubuntu2.1 | [unbound 1.24.2-1ubuntu2.1](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-unbound-1.24.2-1ubuntu2.1.md) | May 19, 2026 |
| Linux | unbound opensuse-leap 16.0 | 1.24.1-160000.2.1 | [OPENSUSE-SU-2026:21083-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21083-1.md) | Jun 18, 2026 |
| Linux | unbound sles 16.0 | 1.24.1-160000.2.1 | [SUSE-SU-2026:22160-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22160-1.md) | Jun 18, 2026 |
| Linux | unbound-anchor Ubuntu 22.04.1 LTS (jammy) | 1.13.1-1ubuntu5.15 | [unbound-anchor 1.13.1-1ubuntu5.15](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-unbound-anchor-1.13.1-1ubuntu5.15.md) | May 27, 2026 |
| Linux | unbound-anchor Ubuntu 24.04.5 LTS (noble) | 1.19.2-1ubuntu3.8 | [unbound-anchor 1.19.2-1ubuntu3.8](https://patchblox.com/security/data/fix/linux/ubuntu-noble-unbound-anchor-1.19.2-1ubuntu3.8.md) | May 27, 2026 |
| Linux | unbound-anchor Ubuntu 25.10 (questing) | 1.22.0-2ubuntu2.3 | [unbound-anchor 1.22.0-2ubuntu2.3](https://patchblox.com/security/data/fix/linux/ubuntu-questing-unbound-anchor-1.22.0-2ubuntu2.3.md) | May 27, 2026 |
| Linux | unbound-anchor Ubuntu 26.04.1 LTS (resolute) | 1.24.2-1ubuntu2.1 | [unbound-anchor 1.24.2-1ubuntu2.1](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-unbound-anchor-1.24.2-1ubuntu2.1.md) | May 19, 2026 |
| Linux | unbound-host Ubuntu 22.04.1 LTS (jammy) | 1.13.1-1ubuntu5.15 | [unbound-host 1.13.1-1ubuntu5.15](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-unbound-host-1.13.1-1ubuntu5.15.md) | May 27, 2026 |
| Linux | unbound-host Ubuntu 24.04.5 LTS (noble) | 1.19.2-1ubuntu3.8 | [unbound-host 1.19.2-1ubuntu3.8](https://patchblox.com/security/data/fix/linux/ubuntu-noble-unbound-host-1.19.2-1ubuntu3.8.md) | May 27, 2026 |
| Linux | unbound-host Ubuntu 25.10 (questing) | 1.22.0-2ubuntu2.3 | [unbound-host 1.22.0-2ubuntu2.3](https://patchblox.com/security/data/fix/linux/ubuntu-questing-unbound-host-1.22.0-2ubuntu2.3.md) | May 27, 2026 |
| Linux | unbound-host Ubuntu 26.04.1 LTS (resolute) | 1.24.2-1ubuntu2.1 | [unbound-host 1.24.2-1ubuntu2.1](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-unbound-host-1.24.2-1ubuntu2.1.md) | May 19, 2026 |

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Data as of 2026-11-08T13:06:02Z 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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