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CVE-2026-19033 (GCVE-0-2026-19033)

Vulnerability from cvelistv5 – Published: 2026-09-16 14:10 – Updated: 2026-09-16 14:10
VLAI
Title
Unauthenticated IXFR deltas are applied to the live zone before TSIG verification
Summary
For a secondary zone with transfers restricted by TSIG, `named` may start to serve the data provided in a zone transfer before the final message with the TSIG signature arrives. This could allow an attacker that does not actually possess a valid TSIG signature to send unauthorized zone contents to a secondary server. Although no TSIG signature ever arrives, `named` does not rollback to the pre-transfer state. To exploit the vulnerability, the transfer must be a multi-message TCP IXFR, as described by RFC 8945. This issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.27-S1.
Severity
6.5 (Medium)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:L
CWE
  • CWE-349 - Acceptance of Extraneous Untrusted Data With Trusted Data
Assigner
References
Impacted products
Vendor Product Version CPE status
ISC BIND 9 Affected: 9.11.0 , ≤ 9.18.50 (custom)
Affected: 9.20.0 , ≤ 9.20.27 (custom)
Affected: 9.21.0 , ≤ 9.21.25 (custom)
Affected: 9.11.3-S1 , ≤ 9.18.50-S1 (custom)
Affected: 9.20.9-S1 , ≤ 9.20.27-S1 (custom)
    cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*
    cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*
    cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*
    cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*
    cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*
Create a notification for this product.
Date Public
2026-09-16 00:00
Show details on NVD website
To clipboard 

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          "vendor": "ISC",
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      "descriptions": [
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      "exploits": [
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      "impacts": [
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            "baseScore": 6.5,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:L",
            "version": "3.1"
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      "problemTypes": [
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              "description": "CWE-349 Acceptance of Extraneous Untrusted Data With Trusted Data",
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        "orgId": "404fd4d2-a609-4245-b543-2c944a302a22",
        "shortName": "isc"
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          "name": "CVE-2026-19033",
          "tags": [
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          "url": "https://kb.isc.org/docs/cve-2026-19033"
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          "url": "https://downloads.isc.org/isc/bind9/9.20.29"
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          "url": "https://downloads.isc.org/isc/bind9/9.21.26"
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      "solutions": [
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          "lang": "en",
          "value": "Upgrade to the patched release most closely related to your current version of BIND 9: 9.20.29, 9.21.26, or 9.20.29-S1."
        }
      ],
      "source": {
        "discovery": "INTERNAL"
      },
      "title": "Unauthenticated IXFR deltas are applied to the live zone before TSIG verification",
      "workarounds": [
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          "value": "No workarounds known."
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    "datePublished": "2026-09-16T14:10:08.535Z",
    "dateReserved": "2026-08-06T04:18:09.842Z",
    "dateUpdated": "2026-09-16T14:10:08.535Z",
    "state": "PUBLISHED"
  },
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  "dataVersion": "5.2",
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    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-09-17T08:37:15+00:00",
      "cve": "CVE-2026-19033",
      "id": "CVE-2026-19033",
      "initial_release_date": "2026-09-16T14:10:08.535000+00:00",
      "product_status:known_affected": "3",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "bind: BIND: Unauthorized zone content updates via unauthenticated IXFR deltas",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-19033.json",
      "version": "3"
    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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