SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2023-6516

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.

HIGH 7.5EPSS 1.11%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.11%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1
7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
1.11% probability · 66th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-770, CWE-789
Affected
isc/bind · netapp/active iq unified manager
Source
security-officer@isc.org
EPSS trend
0%3%5%27 October 2026: 1.11%27 October 202627 October 2026

EPSS 1.1% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.