# CVE-2026-80225: Possible degradation of service from continuous queries on the same TCP/DoT connection CVE-2026-80225 is fixed in 15 products on 1 platform, first by libunbound8 1.9.4-2ubuntu1.11+esm3, released September 16, 2026. It is not reported as exploited. Patch Radar priority: High. - Web page: https://patchblox.com/security/cve/CVE-2026-80225 - Priority: High - CVSS: 7.5 (Moderate) - EPSS: 0.0048 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Sep 16, 2026 - Weakness: Allocation of Resources Without Limits or Throttling - Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-80225 ## Description In NLnetLabs Unbound up to and including 1.26.0, a degradation of service vulnerability is present in the TCP/DoT reading procedure where there is no limit on consecutive reads. A malicious actor that can stream and sustain a rate of distinct uncached names over the TCP/DoT connection, monopolizes a single worker's entire event loop for as long as its writes stay ahead of the drain. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | libunbound8 Ubuntu 20.04 LTS (focal) | 1.9.4-2ubuntu1.11+esm3 | [libunbound8 1.9.4-2ubuntu1.11+esm3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-libunbound8-1.9.4-2ubuntu1.11-esm3.md) | Sep 16, 2026 | | Linux | libunbound8 Ubuntu 22.04.1 LTS (jammy) | 1.13.1-1ubuntu5.17 | [libunbound8 1.13.1-1ubuntu5.17](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-libunbound8-1.13.1-1ubuntu5.17.md) | Sep 16, 2026 | | Linux | libunbound8 Ubuntu 24.04.5 LTS (noble) | 1.19.2-1ubuntu3.12 | [libunbound8 1.19.2-1ubuntu3.12](https://patchblox.com/security/data/fix/linux/ubuntu-noble-libunbound8-1.19.2-1ubuntu3.12.md) | Sep 16, 2026 | | Linux | libunbound8 Ubuntu 26.04.1 LTS (resolute) | 1.24.2-1ubuntu2.4 | [libunbound8 1.24.2-1ubuntu2.4](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-libunbound8-1.24.2-1ubuntu2.4.md) | Sep 16, 2026 | | Linux | python-unbound Ubuntu 20.04 LTS (focal) | 1.9.4-2ubuntu1.11+esm3 | [python-unbound 1.9.4-2ubuntu1.11+esm3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-python-unbound-1.9.4-2ubuntu1.11-esm3.md) | Sep 16, 2026 | | Linux | python3-unbound Ubuntu 20.04 LTS (focal) | 1.9.4-2ubuntu1.11+esm3 | [python3-unbound 1.9.4-2ubuntu1.11+esm3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-python3-unbound-1.9.4-2ubuntu1.11-esm3.md) | Sep 16, 2026 | | Linux | python3-unbound Ubuntu 22.04.1 LTS (jammy) | 1.13.1-1ubuntu5.17 | [python3-unbound 1.13.1-1ubuntu5.17](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-python3-unbound-1.13.1-1ubuntu5.17.md) | Sep 16, 2026 | | Linux | python3-unbound Ubuntu 24.04.5 LTS (noble) | 1.19.2-1ubuntu3.12 | [python3-unbound 1.19.2-1ubuntu3.12](https://patchblox.com/security/data/fix/linux/ubuntu-noble-python3-unbound-1.19.2-1ubuntu3.12.md) | Sep 16, 2026 | | Linux | python3-unbound Ubuntu 26.04.1 LTS (resolute) | 1.24.2-1ubuntu2.4 | [python3-unbound 1.24.2-1ubuntu2.4](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-python3-unbound-1.24.2-1ubuntu2.4.md) | Sep 16, 2026 | | Linux | python3-unbound amzn 2023 | 1.17.1-1.amzn2023.0.15 | [ALAS2023-2026-3127](https://patchblox.com/security/data/fix/linux/alas2023-2026-3127.md) | Sep 28, 2026 | | Linux | python3-unbound-debuginfo amzn 2023 | 1.17.1-1.amzn2023.0.15 | [ALAS2023-2026-3127](https://patchblox.com/security/data/fix/linux/alas2023-2026-3127.md) | Sep 28, 2026 | | Linux | unbound Debian 13.5 (trixie) | 1.26.1-0+deb13u1 | [DEBIAN-CVE-2026-80225](https://patchblox.com/security/data/fix/linux/debian-cve-2026-80225.md) | Sep 19, 2026 | | Linux | unbound Debian 14 | 1.26.1-1 | [DEBIAN-CVE-2026-80225](https://patchblox.com/security/data/fix/linux/debian-cve-2026-80225.md) | Sep 19, 2026 | | Linux | unbound Ubuntu 20.04 LTS (focal) | 1.9.4-2ubuntu1.11+esm3 | [unbound 1.9.4-2ubuntu1.11+esm3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-unbound-1.9.4-2ubuntu1.11-esm3.md) | Sep 16, 2026 | | Linux | unbound Ubuntu 22.04.1 LTS (jammy) | 1.13.1-1ubuntu5.17 | [unbound 1.13.1-1ubuntu5.17](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-unbound-1.13.1-1ubuntu5.17.md) | Sep 16, 2026 | | Linux | unbound Ubuntu 24.04.5 LTS (noble) | 1.19.2-1ubuntu3.12 | [unbound 1.19.2-1ubuntu3.12](https://patchblox.com/security/data/fix/linux/ubuntu-noble-unbound-1.19.2-1ubuntu3.12.md) | Sep 16, 2026 | | Linux | unbound Ubuntu 26.04.1 LTS (resolute) | 1.24.2-1ubuntu2.4 | [unbound 1.24.2-1ubuntu2.4](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-unbound-1.24.2-1ubuntu2.4.md) | Sep 16, 2026 | | Linux | unbound amzn 2023 | 1.17.1-1.amzn2023.0.15 | [ALAS2023-2026-3127](https://patchblox.com/security/data/fix/linux/alas2023-2026-3127.md) | Sep 28, 2026 | | Linux | unbound opensuse-leap 16.0 | 1.26.1-160000.1.1 | [OPENSUSE-SU-2026:22082-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22082-1.md) | Nov 7, 2026 | | Linux | unbound sles 15.6 | 1.26.1-150600.23.24.1 | [SUSE-SU-2026:4620-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4620-1.md) | Nov 7, 2026 | | Linux | unbound sles 15.7 | 1.26.1-150600.23.24.1 | [SUSE-SU-2026:4620-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4620-1.md) | Nov 7, 2026 | | Linux | unbound sles 16.0 | 1.26.1-160000.1.1 | [SUSE-SU-2026:24226-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24226-1.md) | Nov 7, 2026 | | Linux | unbound-anchor Ubuntu 20.04 LTS (focal) | 1.9.4-2ubuntu1.11+esm3 | [unbound-anchor 1.9.4-2ubuntu1.11+esm3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-unbound-anchor-1.9.4-2ubuntu1.11-esm3.md) | Sep 16, 2026 | | Linux | unbound-anchor Ubuntu 22.04.1 LTS (jammy) | 1.13.1-1ubuntu5.17 | [unbound-anchor 1.13.1-1ubuntu5.17](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-unbound-anchor-1.13.1-1ubuntu5.17.md) | Sep 16, 2026 | | Linux | unbound-anchor Ubuntu 24.04.5 LTS (noble) | 1.19.2-1ubuntu3.12 | [unbound-anchor 1.19.2-1ubuntu3.12](https://patchblox.com/security/data/fix/linux/ubuntu-noble-unbound-anchor-1.19.2-1ubuntu3.12.md) | Sep 16, 2026 | | Linux | unbound-anchor Ubuntu 26.04.1 LTS (resolute) | 1.24.2-1ubuntu2.4 | [unbound-anchor 1.24.2-1ubuntu2.4](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-unbound-anchor-1.24.2-1ubuntu2.4.md) | Sep 16, 2026 | | Linux | unbound-anchor amzn 2023 | 1.17.1-1.amzn2023.0.15 | [ALAS2023-2026-3127](https://patchblox.com/security/data/fix/linux/alas2023-2026-3127.md) | Sep 28, 2026 | | Linux | unbound-anchor-debuginfo amzn 2023 | 1.17.1-1.amzn2023.0.15 | [ALAS2023-2026-3127](https://patchblox.com/security/data/fix/linux/alas2023-2026-3127.md) | Sep 28, 2026 | | Linux | unbound-debuginfo amzn 2023 | 1.17.1-1.amzn2023.0.15 | [ALAS2023-2026-3127](https://patchblox.com/security/data/fix/linux/alas2023-2026-3127.md) | Sep 28, 2026 | | Linux | unbound-debugsource amzn 2023 | 1.17.1-1.amzn2023.0.15 | [ALAS2023-2026-3127](https://patchblox.com/security/data/fix/linux/alas2023-2026-3127.md) | Sep 28, 2026 | | Linux | unbound-devel amzn 2023 | 1.17.1-1.amzn2023.0.15 | [ALAS2023-2026-3127](https://patchblox.com/security/data/fix/linux/alas2023-2026-3127.md) | Sep 28, 2026 | | Linux | unbound-host Ubuntu 20.04 LTS (focal) | 1.9.4-2ubuntu1.11+esm3 | [unbound-host 1.9.4-2ubuntu1.11+esm3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-unbound-host-1.9.4-2ubuntu1.11-esm3.md) | Sep 16, 2026 | | Linux | unbound-host Ubuntu 22.04.1 LTS (jammy) | 1.13.1-1ubuntu5.17 | [unbound-host 1.13.1-1ubuntu5.17](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-unbound-host-1.13.1-1ubuntu5.17.md) | Sep 16, 2026 | | Linux | unbound-host Ubuntu 24.04.5 LTS (noble) | 1.19.2-1ubuntu3.12 | [unbound-host 1.19.2-1ubuntu3.12](https://patchblox.com/security/data/fix/linux/ubuntu-noble-unbound-host-1.19.2-1ubuntu3.12.md) | Sep 16, 2026 | | Linux | unbound-host Ubuntu 26.04.1 LTS (resolute) | 1.24.2-1ubuntu2.4 | [unbound-host 1.24.2-1ubuntu2.4](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-unbound-host-1.24.2-1ubuntu2.4.md) | Sep 16, 2026 | | Linux | unbound-libs amzn 2023 | 1.17.1-1.amzn2023.0.15 | [ALAS2023-2026-3127](https://patchblox.com/security/data/fix/linux/alas2023-2026-3127.md) | Sep 28, 2026 | | Linux | unbound-libs-debuginfo amzn 2023 | 1.17.1-1.amzn2023.0.15 | [ALAS2023-2026-3127](https://patchblox.com/security/data/fix/linux/alas2023-2026-3127.md) | Sep 28, 2026 | | Linux | unbound-utils amzn 2023 | 1.17.1-1.amzn2023.0.15 | [ALAS2023-2026-3127](https://patchblox.com/security/data/fix/linux/alas2023-2026-3127.md) | Sep 28, 2026 | | Linux | unbound-utils-debuginfo amzn 2023 | 1.17.1-1.amzn2023.0.15 | [ALAS2023-2026-3127](https://patchblox.com/security/data/fix/linux/alas2023-2026-3127.md) | Sep 28, 2026 | --- Data as of 2026-11-08T00:53:09Z UTC. 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