CVE-2026-96405 (GCVE-0-2026-96405)
Vulnerability from cvelistv5
Published
2026-10-21 08:57
Modified
2026-10-21 08:57
CWE
  • CWE-770 - Allocation of Resources Without Limits or Throttling
Summary
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.
Impacted products
Vendor Product Version
NLnet Labs Unbound Version: 0   ≤
Create a notification for this product.
Show details on NVD website


{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Unbound",
          "vendor": "NLnet Labs",
          "versions": [
            {
              "lessThan": "1.26.2",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Yuheng Zhang (Tsinghua University \u0026 Jingxian Technology Co., Ltd.)"
        },
        {
          "lang": "en",
          "type": "finder",
          "value": "Jianjun Chen (Tsinghua University)"
        },
        {
          "lang": "en",
          "type": "finder",
          "value": "Zihan Wang (Z.AI Co., Ltd.)"
        },
        {
          "lang": "en",
          "type": "finder",
          "value": "Kaiwen Shen (CloudItera)"
        }
      ],
      "datePublic": "2026-10-21T00:00:00.000Z",
      "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\u0027s general performance."
        }
      ],
      "metrics": [
        {
          "cvssV3_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",
            "version": "3.1"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-770",
              "description": "CWE-770: Allocation of Resources Without Limits or Throttling",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-21T08:57:26.986Z",
        "orgId": "206fc3a0-e175-490b-9eaa-a5738056c9f6",
        "shortName": "NLnet Labs"
      },
      "references": [
        {
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-96405.txt"
        }
      ],
      "solutions": [
        {
          "lang": "en",
          "value": "This issue is fixed starting with version 1.26.2"
        }
      ],
      "timeline": [
        {
          "lang": "en",
          "time": "2026-07-16T00:00:00.000Z",
          "value": "Issue reported by Yuheng Zhang"
        },
        {
          "lang": "en",
          "time": "2026-07-17T00:00:00.000Z",
          "value": "NLnet Labs shares patch"
        },
        {
          "lang": "en",
          "time": "2026-07-17T00:00:00.000Z",
          "value": "Yuheng Zhang requests changes"
        },
        {
          "lang": "en",
          "time": "2026-07-21T00:00:00.000Z",
          "value": "NLnet Labs shares new patch"
        },
        {
          "lang": "en",
          "time": "2026-09-30T00:00:00.000Z",
          "value": "Yuheng Zhang verifies patch"
        },
        {
          "lang": "en",
          "time": "2026-09-16T00:00:00.000Z",
          "value": "Coordinated fixes released with version 1.26.2"
        }
      ],
      "title": "Aggregate DNS name chained pointer decompression work leads to degradation of service.",
      "x_generator": {
        "engine": "cvelib 1.8.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "206fc3a0-e175-490b-9eaa-a5738056c9f6",
    "assignerShortName": "NLnet Labs",
    "cveId": "CVE-2026-96405",
    "datePublished": "2026-10-21T08:57:26.986Z",
    "dateReserved": "2026-10-14T09:16:14.093Z",
    "dateUpdated": "2026-10-21T08:57:26.986Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.


Loading…

Loading…

Loading…

Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.


Loading…

Loading…