{"id":"CVE-2026-96405","state":"PUBLISHED","title":"Aggregate DNS name chained pointer decompression work leads to degradation of service.","description":"NLnet Labs Unbound up to and including version 1.26.1 limits compression-pointer traversal for each individual domain-name operation but has no aggregate inbound decompression-work budget. Many chained compression pointers in a message results in a lot of CPU usage following them. A malicious actor with recursive-query access and control of an ordinarily delegated authority that serves specially crafted replies can exploit the vulnerability and degrade Unbound's general performance.","publishedAt":"2026-10-21T08:57:26.986Z","updatedAt":"2026-10-29T19:07:33.197Z","severity":{"score":5.3,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","source":"NLnet Labs"},"assigner":"NLnet Labs","products":["NLnet Labs Unbound"],"affected":[{"vendor":"NLnet Labs","product":"Unbound","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"1.26.2","versionType":"semver"}]}],"references":["https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-96405.txt"],"weaknesses":["CWE-770"],"ingestedAt":"2026-10-29T20:13:43.249Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/96xxx/CVE-2026-96405.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-96405","state":"PUBLISHED","datePublished":"2026-10-21T08:57:26.986Z","dateUpdated":"2026-10-29T19:07:33.197Z","assignerShortName":"NLnet Labs","assignerOrgId":"206fc3a0-e175-490b-9eaa-a5738056c9f6","dateReserved":"2026-10-14T09:16:14.093Z"},"containers":{"cna":{"title":"Aggregate DNS name chained pointer decompression work leads to degradation of service.","descriptions":[{"lang":"en","value":"NLnet Labs Unbound up to and including version 1.26.1 limits compression-pointer traversal for each individual domain-name operation but has no aggregate inbound decompression-work budget. Many chained compression pointers in a message results in a lot of CPU usage following them. A malicious actor with recursive-query access and control of an ordinarily delegated authority that serves specially crafted replies can exploit the vulnerability and degrade Unbound's general performance."}],"affected":[{"vendor":"NLnet Labs","product":"Unbound","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"1.26.2","versionType":"semver"}]}],"references":[{"url":"https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-96405.txt","tags":["vendor-advisory"]}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV3_1":{"version":"3.1","baseScore":5.3,"baseSeverity":"MEDIUM","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-770","lang":"en","description":"CWE-770: Allocation of Resources Without Limits or Throttling","type":"CWE"}]}],"providerMetadata":{"shortName":"NLnet Labs","orgId":"206fc3a0-e175-490b-9eaa-a5738056c9f6","dateUpdated":"2026-10-21T08:57:26.986Z"},"datePublic":"2026-10-21T00:00:00.000Z","solutions":[{"lang":"en","value":"This issue is fixed starting with version 1.26.2"}],"timeline":[{"time":"2026-07-16T00:00:00.000Z","lang":"en","value":"Issue reported by Yuheng Zhang"},{"time":"2026-07-17T00:00:00.000Z","lang":"en","value":"NLnet Labs shares patch"},{"time":"2026-07-17T00:00:00.000Z","lang":"en","value":"Yuheng Zhang requests changes"},{"time":"2026-07-21T00:00:00.000Z","lang":"en","value":"NLnet Labs shares new patch"},{"time":"2026-09-30T00:00:00.000Z","lang":"en","value":"Yuheng Zhang verifies patch"},{"time":"2026-09-16T00:00:00.000Z","lang":"en","value":"Coordinated fixes released with version 1.26.2"}],"credits":[{"lang":"en","value":"Yuheng Zhang (Tsinghua University & Jingxian Technology Co., Ltd.)","type":"finder"},{"lang":"en","value":"Jianjun Chen (Tsinghua University)","type":"finder"},{"lang":"en","value":"Zihan Wang (Z.AI Co., Ltd.)","type":"finder"},{"lang":"en","value":"Kaiwen Shen (CloudItera)","type":"finder"}],"x_generator":{"engine":"cvelib 1.8.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-29T19:07:13.696474Z","id":"CVE-2026-96405","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-29T19:07:33.197Z"}}]}}}