Security advisory
To keep its cache database efficient, `named` running as a recursive resolver occasionally attempts to clean up the database. It uses several methods, including some that are asynchronous: a small chunk of memory pointing to the cache element that can be cleaned up is first allocated and then queued for later processing. It was discovered that if the resolver is continuously processing query patterns triggering this type of cache-database maintenance, `named` may not be able to handle the cleanup events in a timely manner. This in turn enables the list of queued cleanup events to grow infinitely large over time, allowing the configured `max-cache-size` limit to be significantly exceeded. This issue affects BIND 9 versions 9.16.0 through 9.16.45 and 9.16.8-S1 through 9.16.45-S1.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2023-6516
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 06:09 UTC · Revision 1
Source evidence
To keep its cache database efficient, `named` running as a recursive resolver occasionally attempts to clean up the database. It uses several methods, including some that are asynchronous: a small chunk of memory pointing to the cache element that can be cleaned up is first allocated and then queued for later processing. It was discovered that if the resolver is continuously processing query patterns triggering this type of cache-database maintenance, `named` may not be able to handle the cleanup events in a timely manner. This in turn enables the list of queued cleanup events to grow infinitely large over time, allowing the configured `max-cache-size` limit to be significantly exceeded. This issue affects BIND 9 versions 9.16.0 through 9.16.45 and 9.16.8-S1 through 9.16.45-S1.
osv:CVE-2023-6516
Complete source record
{
"id": "83d3575fdb3fe5e2bbc5f20bef8905f63070bca3717bd796296c441f9ffae00f",
"url": "https://osv.dev/vulnerability/CVE-2023-6516",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2023-6516",
"summary": "To keep its cache database efficient, `named` running as a recursive resolver occasionally attempts to clean up the database. It uses several methods, including some that are asynchronous: a small chunk of memory pointing to the cache element that can be cleaned up is first allocated and then queued for later processing. It was discovered that if the resolver is continuously processing query patterns triggering this type of cache-database maintenance, `named` may not be able to handle the cleanup events in a timely manner. This in turn enables the list of queued cleanup events to grow infinitely large over time, allowing the configured `max-cache-size` limit to be significantly exceeded. This issue affects BIND 9 versions 9.16.0 through 9.16.45 and 9.16.8-S1 through 9.16.45-S1.",
"evidence": "osv:CVE-2023-6516",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2023-6516",
"aliases": [
"CVE-2023-6516"
],
"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": "6270e602ea52209243475c4f1edbabe084e148f7"
},
{
"last_affected": "353fb4b9d32dba44574853568c749c6032a5554e"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:*",
"range": [
{
"introduced": "9.16.0"
},
{
"last_affected": "9.16.45"
}
],
"source": "CPE_RANGE"
}
]
}
}
],
"versions": [
"v9.16.45-release",
"v9.16.45",
"v9.16.0"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-6516.json"
}
},
{
"ranges": [
{
"repo": "https://gitlab.isc.org/isc-projects/bind9",
"type": "GIT",
"events": [
{
"introduced": "6270e602ea52209243475c4f1edbabe084e148f7"
},
{
"last_affected": "353fb4b9d32dba44574853568c749c6032a5554e"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:*",
"range": [
{
"introduced": "9.16.0"
},
{
"last_affected": "9.16.45"
}
],
"source": "CPE_RANGE"
}
]
}
}
],
"versions": [
"v9.16.45",
"v9.16.0"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-6516.json"
}
}
],
"modified": "2026-10-24T10:30:36.146074235Z",
"provider": "osv",
"references": [
"https://kb.isc.org/docs/cve-2023-6516",
"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/PNNHZSZPG2E7NBMBNYPGHCFI4V4XRWNQ/",
"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ZDZFMEKQTZ4L7RY46FCENWFB5MDT263R/",
"https://security.netapp.com/advisory/ntap-20240503-0008/"
],
"provider_metadata": {
"unresolved_ranges": [
{
"cpes": [
"cpe:2.3:a:isc:bind:9.16.11:s1:*:*:supported_preview:*:*:*",
"cpe:2.3:a:isc:bind:9.16.12:s1:*:*:supported_preview:*:*:*",
"cpe:2.3:a:isc:bind:9.16.13:s1:*:*:supported_preview:*:*:*",
"cpe:2.3:a:isc:bind:9.16.14:s1:*:*:supported_preview:*:*:*",
"cpe:2.3:a:isc:bind:9.16.21:s1:*:*:supported_preview:*:*:*",
"cpe:2.3:a:isc:bind:9.16.32:s1:*:*:supported_preview:*:*:*",
"cpe:2.3:a:isc:bind:9.16.36:s1:*:*:supported_preview:*:*:*",
"cpe:2.3:a:isc:bind:9.16.43:s1:*:*:supported_preview:*:*:*",
"cpe:2.3:a:isc:bind:9.16.45:s1:*:*:supported_preview:*:*:*",
"cpe:2.3:a:isc:bind:9.16.8:s1:*:*:supported_preview:*:*:*"
],
"vendor_product": "isc:bind",
"extracted_events": [
{
"range": [
{
"introduced": "9.16.8-s1"
},
{
"last_affected": "9.16.8-s1"
},
{
"introduced": "9.16.8-s1"
},
{
"last_affected": "9.16.8-s1"
},
{
"introduced": "9.16.11-s1"
},
{
"last_affected": "9.16.11-s1"
},
{
"introduced": "9.16.11-s1"
},
{
"last_affected": "9.16.11-s1"
},
{
"introduced": "9.16.12-s1"
},
{
"last_affected": "9.16.12-s1"
},
{
"introduced": "9.16.12-s1"
},
{
"last_affected": "9.16.12-s1"
},
{
"introduced": "9.16.13-s1"
},
{
"last_affected": "9.16.13-s1"
},
{
"introduced": "9.16.13-s1"
},
{
"last_affected": "9.16.13-s1"
},
{
"introduced": "9.16.14-s1"
},
{
"last_affected": "9.16.14-s1"
},
{
"introduced": "9.16.14-s1"
},
{
"last_affected": "9.16.14-s1"
},
{
"introduced": "9.16.21-s1"
},
{
"last_affected": "9.16.21-s1"
},
{
"introduced": "9.16.21-s1"
},
{
"last_affected": "9.16.21-s1"
},
{
"introduced": "9.16.32-s1"
},
{
"last_affected": "9.16.32-s1"
},
{
"introduced": "9.16.32-s1"
},
{
"last_affected": "9.16.32-s1"
},
{
"introduced": "9.16.36-s1"
},
{
"last_affected": "9.16.36-s1"
},
{
"introduced": "9.16.36-s1"
},
{
"last_affected": "9.16.36-s1"
},
{
"introduced": "9.16.43-s1"
},
{
"last_affected": "9.16.43-s1"
},
{
"introduced": "9.16.43-s1"
},
{
"last_affected": "9.16.43-s1"
},
{
"introduced": "9.16.45-s1"
},
{
"last_affected": "9.16.45-s1"
},
{
"introduced": "9.16.45-s1"
},
{
"last_affected": "9.16.45-s1"
}
],
"source": "CPE_STRING"
}
]
}
]
}
},
"related_cves": [
{
"value": "CVE-2023-6516",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 433907,
"published_at": "2024-02-13T14:15:46.03+00:00"
}