CVE-2026-5950 (GCVE-0-2026-5950)
Vulnerability from cvelistv5
Published
2026-05-20 13:10
Modified
2026-05-20 13:38
CWE
  • CWE-606 - Unchecked Input for Loop Condition
Summary
An unbounded resend loop vulnerability exists in the BIND 9 resolver state machine during bad-server handling, enabling a remote unauthenticated attacker to cause severe resource exhaustion by sending queries that trigger specific retry conditions. This issue affects BIND 9 versions 9.18.36 through 9.18.48, 9.20.8 through 9.20.22, 9.21.7 through 9.21.21, 9.18.36-S1 through 9.18.48-S1, and 9.20.9-S1 through 9.20.22-S1.
Impacted products
Vendor Product Version
ISC BIND 9 Version: 9.18.36   <
Version: 9.20.8   <
Version: 9.21.7   <
Version: 9.18.36-S1   <
Version: 9.20.9-S1   <
Create a notification for this product.
Show details on NVD website


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                "id": "CVE-2026-5950",
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                "role": "CISA Coordinator",
                "timestamp": "2026-05-20T13:38:40.421994Z",
                "version": "2.0.3"
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          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
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        "title": "CISA ADP Vulnrichment"
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          "lang": "en",
          "value": "ISC would like to thank Billy Baraja (BielraX) for bringing this vulnerability to our attention."
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        "orgId": "404fd4d2-a609-4245-b543-2c944a302a22",
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          "name": "CVE-2026-5950",
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          "url": "https://downloads.isc.org/isc/bind9/9.18.49"
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          "url": "https://downloads.isc.org/isc/bind9/9.20.23"
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          "value": "Upgrade to the patched release most closely related to your current version of BIND 9: 9.18.49, 9.20.23, 9.21.22, 9.18.49-S1, or 9.20.23-S1."
        }
      ],
      "source": {
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      "title": "Unbounded resend loop in BIND 9 resolver",
      "workarounds": [
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    "dateReserved": "2026-04-09T06:42:23.953Z",
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    "state": "PUBLISHED"
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  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
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