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.
CVE-2023-6516
Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2024-02-13. NVD baseline CVSS 7.5; sources differ by 0.0.
- High severity, but no confirmed exploitation yet
A fix is available — apply it.
- CVSS v3
- 7.5
- EG Score
- 7.5(medium)
- EPSS
- 61.7%
- KEV
- Not listed
Published
February 13, 2024
Last Modified
November 21, 2024
References (10)
- security-officer@ischttp://www.openwall.com/lists/oss-security/2024/02/13/1
- security-officer@ischttps://kb.isc.org/docs/cve-2023-6516
- security-officer@ischttps://lists.fedoraproject.org/archives/list/[email protected]/message/PNNHZSZPG2E7NBMBNYPGHCFI4V4XRWNQ/
- security-officer@ischttps://lists.fedoraproject.org/archives/list/[email protected]/message/ZDZFMEKQTZ4L7RY46FCENWFB5MDT263R/
- security-officer@ischttps://security.netapp.com/advisory/ntap-20240503-0008/
- af854a3a-2127-422b-91ae-364da2661108http://www.openwall.com/lists/oss-security/2024/02/13/1
- af854a3a-2127-422b-91ae-364da2661108https://kb.isc.org/docs/cve-2023-6516
- af854a3a-2127-422b-91ae-364da2661108https://lists.fedoraproject.org/archives/list/[email protected]/message/PNNHZSZPG2E7NBMBNYPGHCFI4V4XRWNQ/
- af854a3a-2127-422b-91ae-364da2661108https://lists.fedoraproject.org/archives/list/[email protected]/message/ZDZFMEKQTZ4L7RY46FCENWFB5MDT263R/
- af854a3a-2127-422b-91ae-364da2661108https://security.netapp.com/advisory/ntap-20240503-0008/
Vendor Advisories for CVE-2023-6516(7)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
- RHSA-2024:2551Red Hat Product SecurityHigh
Red Hat Security Advisory: bind security update
- RHSA-2024:1803Red Hat Product SecurityHigh
Red Hat Security Advisory: bind and bind-dyndb-ldap security updates
- RHSA-2024:1800Red Hat Product SecurityHigh
Red Hat Security Advisory: bind and bind-dyndb-ldap security updates
- RHSA-2024:1789Red Hat Product SecurityHigh
Red Hat Security Advisory: bind security update
- RHSA-2024:1781Red Hat Product SecurityHigh
Red Hat Security Advisory: bind9.16 security update
- RHSA-2024:1648Red Hat Product SecurityHigh
Red Hat Security Advisory: bind9.16 security update
- RHSA-2024:1647Red Hat Product SecurityHigh
Red Hat Security Advisory: bind9.16 security update
Patch Availability(8)
| Vendor / Ecosystem | Fixed in / Patch | Released | Source |
|---|---|---|---|
| ubuntu | dnsutils (1:9.16.48-0ubuntu0.20.04.1) @ focal | 2026-05-24 | ubuntu |
| redhat | bind-dyndb-ldap-0:11.9-9.el9_4 | 2024-04-30 | redhat |
| redhat | bind-dyndb-ldap-0:11.9-7.el9_0.1 | 2024-04-15 | redhat |
| redhat | bind-dyndb-ldap-0:11.9-8.el9_2.2 | 2024-04-15 | redhat |
| redhat | bind9.16-32:9.16.23-0.16.el8_9.2 | 2024-04-11 | redhat |
| redhat | bind-dyndb-ldap-0:11.9-8.el9_3.3 | 2024-04-11 | redhat |
| redhat | bind9.16-32:9.16.23-0.14.el8_8.4 | 2024-04-02 | redhat |
| redhat | bind9.16-32:9.16.23-0.7.el8_6.5 | 2024-04-02 | redhat |
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Additional Vendor Advisories
(2)
Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.
Data Freshness Timeline
(refreshed 10× in last 7d / 43× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-11 08:26 UTCEPSS rescore
- 2026-07-09 19:08 UTCEPSS rescore
- 2026-07-08 15:13 UTCEPSS rescore
- 2026-07-07 13:45 UTCEPSS rescore
- 2026-07-07 13:44 UTCEPSS rescore
- 2026-07-06 16:26 UTCEPSS rescore
- 2026-07-06 16:26 UTCEPSS rescore
- 2026-07-06 02:22 UTCEPSS rescore
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- 2026-07-05 02:29 UTCEPSS rescore
- 2026-07-04 06:29 UTCEPSS rescore
- 2026-07-01 15:05 UTCEPSS rescore
- 2026-06-30 23:21 UTCEPSS rescore
- 2026-06-30 23:21 UTCEPSS rescore
- 2026-06-29 14:05 UTCEPSS rescore
- 2026-06-28 14:06 UTCEPSS rescore
- 2026-06-28 14:06 UTCEPSS rescore
- 2026-06-28 04:55 UTCEPSS rescore
- 2026-06-27 03:07 UTCEPSS rescore
- 2026-06-26 20:39 UTCOSV refresh
- 2026-06-25 13:48 UTCEPSS rescore
- 2026-06-25 13:48 UTCEPSS rescore
- 2026-06-24 14:04 UTCEPSS rescore
- 2026-06-24 14:04 UTCEPSS rescore
- 2026-06-23 21:31 UTCEPSS rescore
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- 2026-06-23 21:31 UTCEPSS rescore
- 2026-06-22 14:24 UTCEPSS rescore
- 2026-06-22 14:24 UTCEPSS rescore
- 2026-06-21 14:55 UTCEPSS rescore
- 2026-06-21 14:55 UTCEPSS rescore
- 2026-06-21 01:58 UTCEPSS rescore
- 2026-06-21 01:58 UTCEPSS rescore
- 2026-06-19 19:24 UTCEPSS rescore
- 2026-06-19 19:24 UTCEPSS rescore
- 2026-06-18 17:51 UTCEPSS rescore
- 2026-06-17 17:51 UTCEPSS rescore
- 2026-06-16 17:51 UTCEPSS rescore
- 2026-06-16 17:51 UTCEPSS rescore
- 2026-06-15 17:47 UTCEPSS rescore
- 2026-06-14 23:16 UTCEPSS rescore
- 2026-06-13 22:59 UTCEPSS rescore
- 2026-06-13 22:59 UTCEPSS rescore
- 2026-06-12 23:11 UTCEPSS rescore
- 2026-06-11 13:59 UTCEPSS rescore
- 2026-06-10 22:17 UTCEPSS rescore
- 2026-06-10 13:21 UTCEPSS rescore
- 2026-06-09 07:00 UTCOSV refresh
- 2026-06-08 14:16 UTCEPSS rescore
- 2026-06-08 14:16 UTCEPSS rescore
- 2026-06-07 15:24 UTCEPSS rescore
- 2026-06-07 15:24 UTCEPSS rescore
- 2026-06-06 13:46 UTCEPSS rescore
- 2026-06-06 13:46 UTCEPSS rescore
- 2026-06-05 22:46 UTCEPSS rescore
- 2026-06-05 22:46 UTCEPSS rescore
- 2026-06-05 06:09 UTCEPSS rescore
- 2026-06-05 06:09 UTCEPSS rescore
- 2026-06-04 13:11 UTCEPSS rescore
- 2026-06-04 13:11 UTCEPSS rescore
- 2026-06-02 20:12 UTCEPSS rescore
- 2026-06-02 20:12 UTCEPSS rescore
- 2026-06-01 13:51 UTCEPSS rescore
- 2026-05-31 22:30 UTCEPSS rescore
- 2026-05-31 22:30 UTCEPSS rescore
- 2026-05-31 00:15 UTCEPSS rescore
- 2026-05-31 00:15 UTCEPSS rescore
- 2026-05-29 13:43 UTCEPSS rescore
- 2026-05-28 13:44 UTCEPSS rescore
- 2026-05-28 13:44 UTCEPSS rescore
- 2026-05-27 13:40 UTCEPSS rescore
- 2026-05-27 13:39 UTCEPSS rescore
- 2026-05-26 13:43 UTCEPSS rescore
- 2026-05-26 13:43 UTCEPSS rescore
- 2026-05-26 07:18 UTCEPSS rescore
- 2026-05-26 07:18 UTCEPSS rescore
- 2026-05-24 08:42 UTCEG score recompute
- 2026-05-24 08:42 UTCVendor advisory
- 2026-05-24 08:42 UTCGHSA enrichment
Frequently asked(5)
What is CVE-2023-6516?
When was CVE-2023-6516 disclosed?
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What is the CVSS score of CVE-2023-6516?
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