High
Security advisory
A flaw in the networking code handling DNS-over-TLS queries may cause `named` to terminate unexpectedly due to an assertion failure. This happens when internal data structures are incorrectly reused under significant DNS-over-TLS query load. This issue affects BIND 9 versions 9.18.0 through 9.18.18 and 9.18.11-S1 through 9.18.18-S1.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2023-4236
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 04:36 UTC · Revision 1
Source evidence
A flaw in the networking code handling DNS-over-TLS queries may cause `named` to terminate unexpectedly due to an assertion failure. This happens when internal data structures are incorrectly reused under significant DNS-over-TLS query load. This issue affects BIND 9 versions 9.18.0 through 9.18.18 and 9.18.11-S1 through 9.18.18-S1.
osv:CVE-2023-4236
Complete source record
{
"id": "a5fa737592d62c44ceb341bbc33b68ecc47614d7cd4a8e776727ba5ef919eb92",
"url": "https://osv.dev/vulnerability/CVE-2023-4236",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2023-4236",
"summary": "A flaw in the networking code handling DNS-over-TLS queries may cause `named` to terminate unexpectedly due to an assertion failure. This happens when internal data structures are incorrectly reused under significant DNS-over-TLS query load. This issue affects BIND 9 versions 9.18.0 through 9.18.18 and 9.18.11-S1 through 9.18.18-S1.",
"evidence": "osv:CVE-2023-4236",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2023-4236",
"aliases": [
"CVE-2023-4236"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/isc-projects/bind9",
"type": "GIT",
"events": [
{
"introduced": "8db45afa1affcb823e68afdeddedf93e136f5d3e"
},
{
"fixed": "1f8de2f0aa6a47e299fbd8e66921fbcb4c5f64dc"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:*",
"range": [
{
"introduced": "9.18.0"
},
{
"fixed": "9.18.18"
}
],
"source": "CPE_RANGE"
}
]
}
}
],
"versions": [
"v9.18.0"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-4236.json"
}
},
{
"ranges": [
{
"repo": "https://gitlab.isc.org/isc-projects/bind9",
"type": "GIT",
"events": [
{
"introduced": "8db45afa1affcb823e68afdeddedf93e136f5d3e"
},
{
"fixed": "1f8de2f0aa6a47e299fbd8e66921fbcb4c5f64dc"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:*",
"range": [
{
"introduced": "9.18.0"
},
{
"fixed": "9.18.18"
}
],
"source": "CPE_RANGE"
}
]
}
}
],
"versions": [
"v9.18.0"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-4236.json"
}
}
],
"modified": "2026-10-24T10:30:20.706679644Z",
"provider": "osv",
"references": [
"https://kb.isc.org/docs/cve-2023-4236",
"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/VSK5V4W4OHPM3JTJGWAQD6CZW7SFD75B/",
"https://security.netapp.com/advisory/ntap-20231013-0004/",
"https://www.debian.org/security/2023/dsa-5504",
"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/IPJLLTJCSDJJII7IIZPLTBQNWP7MZH7F/",
"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/U35OARLQCPMVCBBPHWBXY5M6XJLD2TZ5/"
],
"provider_metadata": {
"unresolved_ranges": [
{
"cpes": [
"cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*",
"cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*"
],
"vendor_product": "debian:debian_linux",
"extracted_events": [
{
"range": [
{
"introduced": "10.0"
},
{
"last_affected": "10.0"
},
{
"introduced": "11.0"
},
{
"last_affected": "11.0"
}
],
"source": "CPE_STRING"
}
]
},
{
"cpes": [
"cpe:2.3:o:fedoraproject:fedora:37:*:*:*:*:*:*:*",
"cpe:2.3:o:fedoraproject:fedora:38:*:*:*:*:*:*:*",
"cpe:2.3:o:fedoraproject:fedora:39:*:*:*:*:*:*:*"
],
"vendor_product": "fedoraproject:fedora",
"extracted_events": [
{
"range": [
{
"introduced": "37"
},
{
"last_affected": "37"
},
{
"introduced": "38"
},
{
"last_affected": "38"
},
{
"introduced": "39"
},
{
"last_affected": "39"
}
],
"source": "CPE_STRING"
}
]
},
{
"cpes": [
"cpe:2.3:a:isc:bind:9.18.11:s1:*:*:supported_preview:*:*:*",
"cpe:2.3:a:isc:bind:9.18.18:s1:*:*:supported_preview:*:*:*"
],
"vendor_product": "isc:bind",
"extracted_events": [
{
"range": [
{
"introduced": "9.18.11-s1"
},
{
"last_affected": "9.18.11-s1"
},
{
"introduced": "9.18.11-s1"
},
{
"last_affected": "9.18.11-s1"
},
{
"introduced": "9.18.18-s1"
},
{
"last_affected": "9.18.18-s1"
},
{
"introduced": "9.18.18-s1"
},
{
"last_affected": "9.18.18-s1"
}
],
"source": "CPE_STRING"
}
]
}
]
}
},
"related_cves": [
{
"value": "CVE-2023-4236",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 430322,
"published_at": "2023-09-20T13:15:12.313+00:00"
}