CVE-2026-12244 (GCVE-0-2026-12244)

Vulnerability from cvelistv5 – Published: 2026-06-25 05:24 – Updated: 2026-06-25 05:24
VLAI
Title
Heap overflow and crash with crafted SVCB RR
Summary
If NSD is configured as secondary for a zone, the primary of that zone can crash NSD with an AXFR containing a DNS message with a special crafted SVCB RR with an rdata size of 65512, that let's an (uint16_t) variable that is used to allocate space needed for the RR wrap (because total size > 65535), causing a heap overflow. The attacker can perform a controlled (RCE class) head write of up to 65509 bytes
Severity
8.7 (High)
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CWE
  • CWE-190 - Integer Overflow or Wraparound
  • CWE-122 - Heap-based Buffer Overflow
Assigner
References
Impacted products
Vendor Product Version
NLnet Labs NSD Affected: 4.14.0 , < 4.14.3 (semver)
Create a notification for this product.
Date Public
2026-06-25 00:00
Credits
Qifan Zhang from Palo Alto Networks
Show details on NVD website
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      "affected": [
        {
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          "product": "NSD",
          "vendor": "NLnet Labs",
          "versions": [
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              "status": "affected",
              "version": "4.14.0",
              "versionType": "semver"
            }
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      "credits": [
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          "lang": "en",
          "type": "finder",
          "value": "Qifan Zhang from Palo Alto Networks"
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      ],
      "datePublic": "2026-06-25T00:00:00.000Z",
      "descriptions": [
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          "lang": "en",
          "value": "If NSD is configured as secondary for a zone, the primary of that zone can crash NSD with an AXFR containing a DNS message with a special crafted SVCB RR with an rdata size of 65512, that let\u0027s an (uint16_t) variable that is used to allocate space needed for the RR wrap (because total size \u003e 65535), causing a heap overflow. The attacker can perform a controlled (RCE class) head write of up to 65509 bytes"
        }
      ],
      "metrics": [
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            "baseScore": 8.7,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
            "version": "4.0"
          },
          "format": "CVSS",
          "scenarios": [
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              "lang": "en",
              "value": "Processing of a zonefile containing a crafted SVCB. These can be provided by a trusted primary"
            }
          ]
        }
      ],
      "problemTypes": [
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          "descriptions": [
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              "description": "CWE-190: Integer Overflow or Wraparound",
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              "type": "CWE"
            },
            {
              "cweId": "CWE-122",
              "description": "CWE-122: Heap-based Buffer Overflow",
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              "type": "CWE"
            }
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      "providerMetadata": {
        "dateUpdated": "2026-06-25T05:24:08.548Z",
        "orgId": "206fc3a0-e175-490b-9eaa-a5738056c9f6",
        "shortName": "NLnet Labs"
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          "tags": [
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          "url": "https://www.nlnetlabs.nl/downloads/nsd/CVE-2026-12244.txt"
        }
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      "solutions": [
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          "lang": "en",
          "value": "This issue is fixed starting with version 4.14.3."
        }
      ],
      "timeline": [
        {
          "lang": "en",
          "time": "2026-05-28T00:00:00.000Z",
          "value": "Issue reported by Qifan Zhang"
        },
        {
          "lang": "en",
          "time": "2026-06-12T00:00:00.000Z",
          "value": "NLnet Labs shares patch"
        },
        {
          "lang": "en",
          "time": "2026-06-15T00:00:00.000Z",
          "value": "Qifan Zhang verifies patch"
        },
        {
          "lang": "en",
          "time": "2026-06-25T00:00:00.000Z",
          "value": "Fix released with version 4.14.3"
        }
      ],
      "title": "Heap overflow and crash with crafted SVCB RR",
      "x_generator": {
        "engine": "cvelib 1.8.0"
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  "cveMetadata": {
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    "assignerShortName": "NLnet Labs",
    "cveId": "CVE-2026-12244",
    "datePublished": "2026-06-25T05:24:08.548Z",
    "dateReserved": "2026-06-15T06:46:44.866Z",
    "dateUpdated": "2026-06-25T05:24:08.548Z",
    "state": "PUBLISHED"
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  "dataVersion": "5.2"
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