CVE-2023-6516Specific recursive query patterns may lead to an out-of-memory condition
- 7.5HighCVSS base score
- 1.1%Exploitation in 30 daysEPSS · top 34% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
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.
Timeline
ID reserved
By isc
- 2 months later
· 2 months later
Published
- 12 months later
· 12 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| iscCNA (assigner) | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVDNVD · Modified | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 1.1% · top 34% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.5.
Affected products
What to do
Solution: Upgrade to the patched release most closely related to your current version of BIND 9: 9.16.48 or 9.16.48-S1.
Workaround: No workarounds known.
Exploitation: We are not aware of any active exploits.
References
References5
- CVE-2023-6516 (opens in a new tab)vendor-advisoryx_transferred
- http://www.openwall.com/lists/oss-security/2024/02/13/1 (opens in a new tab)x_transferred
- https://lists.fedoraproject.org/archives/list/[email protected]/message/PNNHZSZPG2E7NBMBNYPGHCFI4V4XRWNQ/ (opens in a new tab)x_transferred
- https://lists.fedoraproject.org/archives/list/[email protected]/message/ZDZFMEKQTZ4L7RY46FCENWFB5MDT263R/ (opens in a new tab)x_transferred
- https://security.netapp.com/advisory/ntap-20240503-0008/ (opens in a new tab)x_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2023-58747 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2023-6516)Record last updated .