CVE-2023-2828 — named's configured cache size limit can be significantly exceeded
Every `named` instance configured to run as a recursive resolver maintains a cache database holding the responses to the queries it has recently sent to authoritative servers. The size limit for that cache database can be configured using the `max-cache-size` statement in the configuration file; it defaults to 90% of the total amount of memory available on the host. When the size of the cache reaches 7/8 of the configured limit, a cache-cleaning algorithm starts to remove expired and/or least-recently used RRsets from the cache, to keep memory use below the configured limit. It has been discovered that the effectiveness of the cache-cleaning algorithm used in `named` can be severely diminished by querying the resolver for specific RRsets in a certain order, effectively allowing the configured `max-cache-size` limit to be significantly exceeded. This issue affects BIND 9 versions 9.11.0 through 9.16.41, 9.18.0 through 9.18.15, 9.19.0 through 9.19.13, 9.11.3-S1 through 9.16.41-S1, and 9.18.11-S1 through 9.18.15-S1.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 3.7% (30-day exploitation probability)+13
- Technical severity (high)+6
- Automatable exploitation (SSVC)+3
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — www.openwall.com (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Debian Debian Linux, Fedoraproject Fedora, Isc Bind…).
- The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes matching the vulnerability class (denial of service), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Debian | Debian Linux | version 10.0version 11.0version 12.0 | Vulnerable | NIST National Vulnerability Database |
| Fedoraproject | Fedora | version 38version 37 | Vulnerable | NIST National Vulnerability Database |
| Isc | Bind | ≥ 9.11.0 and ≤ 9.16.41≥ 9.11.3 and ≤ 9.16.41≥ 9.18.0 and ≤ 9.18.15≥ 9.18.11 and ≤ 9.18.15≥ 9.19.0 and ≤ 9.19.13 | Vulnerable | NIST National Vulnerability Database |
| ISC | BIND 9 | ≥ 9.18.11-S1 and ≤ 9.18.15-S1≥ 9.11.3-S1 and ≤ 9.16.41-S1≥ 9.19.0 and ≤ 9.19.13≥ 9.18.0 and ≤ 9.18.15≥ 9.11.0 and ≤ 9.16.41 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Netapp | Active Iq Unified Manager | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Netapp | H300s Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Netapp | H410c Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Netapp | H410s Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Netapp | H500s Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Netapp | H700s Firmware | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 7.5 | CVSS 3.1 | High | 3.9 | 3.6 | security-officer@isc.org via NIST National Vulnerability Database |
| 7.5 | CVSS 3.1 | High | — | — | GitHub, Inc. via GitHub Security Advisories |
| 7.5 | CVSS 3.1 | High | — | — | isc via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H (score shown at the top: security-officer@isc.org) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
CWE-770 · Allocation of Resources Without Limits or Throttling
EPSS over time FIRST
Oct 24, 2026 → Oct 29, 2026 · 6 reading(s) · max 3.70%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Track CPU/memory spikes and availability drops correlated with request patterns.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · isc/bind 9
- SSVC assessment updated
- Record published
- Fix documented
- Affected products added · isc/bind, debian/debian linux, fedoraproject/fedora, netapp/active iq unified manager, netapp/h500s firmware, netapp/h70
- CVSS changed · 7.5
- Source status changed · → Modified
- Record created in this database
- 2023
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 2× References added · Oct 24, 2026 – Oct 24, 2026
- 1× Official description updated · Oct 24, 2026 – Oct 24, 2026
References
12 on the record
- kb.isc.org/docs/cve-2023-2828
- www.openwall.com/lists/oss-security/2023/06/21/6
- security.netapp.com/advisory/ntap-20230703-0010/
- github.com/advisories/GHSA-v668-ccv8-m5gx
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/U3K6AJ
- security.netapp.com/advisory/ntap-20230703-0010
- lists.debian.org/debian-lts-announce/2023/07/msg00021.html
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/SEFCEV
- nvd.nist.gov/vuln/detail/CVE-2023-2828
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/SEFCEV
- www.debian.org/security/2023/dsa-5439
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/U3K6AJ
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-111497 Google Brotli Unchecked Return Value Vulnerability KEV 8d
- High CVE-2026-97313 Specific RPZ configurations and query patterns may result in an unexpected exit 9d
- High CVE-2026-94300 Concurrent GSS-TSIG messages corrupt memory 9d
- High CVE-2026-96888 Named may terminate unexpectedly when a redirect zone is used with strict QNAME minimization 9d
- High CVE-2026-19630 Amplified resource exhaustion in inbound message processing 9d
- High CVE-2026-80274 Validating resolver can abort while caching a mismatched NOQNAME proof Sep 16, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2023-2828 is "named's configured cache size limit can be significantly exceeded", rated High. It affects Debian Linux (Debian); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.5 describes technical severity. EPSS 3.70% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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