ISC Vulnerabilities and Affected Products
Vulnerabilities associated with BIND 9.
Products
Clear product| Vulnerability | Title and context | CVSS | EPSS | PoCs | Signals | STIX action |
|---|---|---|---|---|---|---|
CVE-2026-13321HIGH | DNSSEC Validation Bypass via Out-of-Zone NSEC Next FieldThe BIND resolver accepts validly-signed NSEC records where the "Next Domain Name" field points outside the signer's zone. This issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.24-S1. CWE-346Jul 22, 2026 | CVSS8.6v3.1 | EPSS0.217% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2026-13204HIGH | Unexpected exit in certain situations with NSEC and NSEC3 both presentIf a provably insecure domain is covered by both an NSEC and NSEC3 record at the parent, and there exist an RRSIG for only one of these types, then BIND may exit unexpectedly with an assertion while validating this proof. This issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.24-S1. CWE-617Jul 22, 2026 | CVSS7.5v3.1 | EPSS0.509% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2026-12617HIGH | Record ordering based unexpected exit with CNAME or DNAMEThe issue is unexpected program termination based on ordering and/or specific content in responses to queries for CNAME or DNAME, and A records. Specifically, if a client queries for a DNAME and A record below the DNAME to the resolver, and the authoritative server responds positively to the A query but delays the DNAME response and later responds negatively, `named` may quit unexpectedly. Or, if a client queries for a CNAME and A record for the same name to the resolver, and the authoritative s… CWE-617Jul 22, 2026 | CVSS7.5v3.1 | EPSS0.488% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2026-11721HIGH | Cache poisoning possible with label count discrepancy, RRSIG, and wildcardsIt is possible for an attacker's zone to respond to a query with an RRSIG that has a smaller number of labels than the zone in which the RRSIG is contained. This causes `named` to produce a wildcard name for a zone that is shorter than the attacker's zone, which can result in cache poisoning. For this attack to have any effect, the resolver under attack must have set `synth-from-dnssec yes;` (which is the default). This issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.24… CWE-1284Jul 22, 2026 | CVSS7.5v3.1 | EPSS0.385% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2026-11622HIGH | Potential memory usage beyond configured limitsA DNSSEC validating resolver that is under a random subdomain attack against a DNSSEC-signed zone can suffer from runaway memory usage. The attacker needs to be able to send queries faster than the resolver can perform validation. The increased memory usage can be orders of magnitude beyond the limit configured in the `max-cache-size` parameter. This issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 t… CWE-770Jul 22, 2026 | CVSS7.5v3.1 | EPSS0.509% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2026-11605HIGH | Unnecessary validation of DNSSEC signed recordsThe issue is a resource exhaustion vulnerability associated with DNSSEC validation. BIND always validates all RRSIG records in an answer, even if they are not strictly needed. A query to an authoritative server/zone which returns many valid but superfluous RRSIG records causes the validator to waste disproportionate CPU time. This issue affects BIND 9 versions 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, and 9.20.9-S1 through 9.20.24-S1. CWE-408Jul 22, 2026 | CVSS7.5v3.1 | EPSS0.524% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2026-11331HIGH | Potential wildcard CNAME RPZ policy bypassAn attacker who knows (or guesses) that a resolver uses RPZ with wildcard CNAME policies can craft query names long enough to trigger a NAMETOOLONG error condition during RPZ processing. This is not handled correctly and may lead to defeating the RPZ rule. It also may lead to an unexpected exit of the BIND 9 software. This issue affects BIND 9 versions 9.16.0 through 9.18.50, 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, 9.16.8-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.24-S1. CWE-790Jul 22, 2026 | CVSS7.5v3.1 | EPSS0.416% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2026-10822MEDIUM | Key Record using PRIVATEDNS algorithm may lead to unexpected exitIf BIND encounters a particular invalid data structure in a DNS record, it will accept the invalid data, and may subsequently abort and exit. BIND will first need to store a DNS record for a key (KEY, DNSKEY, etc.). That key must specify a PRIVATEDNS algorithm (253), and in the algorithm identifier, improperly give a length longer than the actual identifier data. The invalid identifier will be stored. If BIND later needs to render that record to text, it will use the invalid length during proce… | CVSS6.5v3.1 | EPSS0.371% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2026-10723MEDIUM | Incorrect acceptance of NSEC3 recordsBIND may accept incorrect child-zone NSEC3 records as valid, which could allow an attacker to forge authenticated NXDOMAIN responses. This issue affects BIND 9 versions 9.18.0 through 9.18.50, 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.24-S1. CWE-347Jul 22, 2026 | CVSS6.8v3.1 | EPSS0.266% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2026-5950MEDIUM | Unbounded resend loop in BIND 9 resolverAn unbounded resend loop vulnerability exists in the BIND 9 resolver state machine during bad-server handling, enabling a remote unauthenticated attacker to cause severe resource exhaustion by sending queries that trigger specific retry conditions. This issue affects BIND 9 versions 9.18.36 through 9.18.48, 9.20.8 through 9.20.22, 9.21.7 through 9.21.21, 9.18.36-S1 through 9.18.48-S1, and 9.20.9-S1 through 9.20.22-S1. CWE-606May 20, 2026 | CVSS5.3v3.1 | EPSS0.66% | PoCs1 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2026-5947HIGH | SIG(0) validation during query flood may lead to undefined behaviorUndefined behavior may result due to a race condition leading to a use-after-free violation. If BIND receives an incoming DNS message signed with SIG(0), it begins work to validate that signature. If, during that validation, the "recursive-clients" limit is reached (as would occur during a query flood), and that same DNS message is discarded per the limit, there is a brief window of time while the SIG(0) validation may attempt to read the now-discarded DNS message. This issue affects BIND 9 ve… | CVSS7.5v3.1 | EPSS1.39% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2026-5946HIGH | Invalid handling of CLASS != INMultiple flaws have been identified in `named` related to the handling of DNS messages whose CLASS is not Internet (`IN`) — for example, `CHAOS` or `HESIOD`, or DNS messages that specify meta-classes (`ANY` or `NONE`) in the question section. Specially crafted requests reaching the affected code paths — recursion, dynamic updates (`UPDATE`), zone change notifications (`NOTIFY`), or processing of `IN`-specific record types in non-`IN` data — can cause assertion failures in `named`. This issue aff… | CVSS7.5v3.1 | EPSS1.87% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2026-3593HIGH | Heap use-after-free vulnerability in BIND 9 DNS-over-HTTPS implementationA use-after-free vulnerability exists within the DNS-over-HTTPS implementation. This issue affects BIND 9 versions 9.20.0 through 9.20.22, 9.21.0 through 9.21.21, and 9.20.9-S1 through 9.20.22-S1. BIND 9 versions 9.18.0 through 9.18.48 and 9.18.11-S1 through 9.18.48-S1 are NOT affected. | CVSS7.4v3.1 | EPSS1.54% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2026-3592MEDIUM | Amplification vulnerabilities via self-pointed glue recordsBIND resolvers are vulnerable to an amplified resource consumption/exhaustion attack. If a victim resolver makes a query to a specially crafted zone, the resolver will consume disproportionate resources. This issue affects BIND 9 versions 9.11.0 through 9.16.50, 9.18.0 through 9.18.48, 9.20.0 through 9.20.22, 9.21.0 through 9.21.21, 9.11.3-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.48-S1, and 9.20.9-S1 through 9.20.22-S1. CWE-408May 20, 2026 | CVSS5.3v3.1 | EPSS0.406% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2026-3039HIGH | BIND 9 server memory exhaustion during GSS-API TKEY negotiationBIND servers that are configured to use TKEY-based authentication via GSS-API tokens are vulnerable to excessive memory consumption when receiving and processing maliciously-constructed packets. Typically these servers will be found in Active Directory integrated DNS deployments and/or Kerberos-secured DNS environments. This issue affects BIND 9 versions 9.0.0 through 9.16.50, 9.18.0 through 9.18.48, 9.20.0 through 9.20.22, 9.21.0 through 9.21.21, 9.9.3-S1 through 9.16.50-S1, 9.18.11-S1 through… | CVSS7.5v3.1 | EPSS1.05% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2026-3591MEDIUM | A stack use-after-return flaw in SIG(0) handling code may enable ACL bypassA use-after-return vulnerability exists in the `named` server when handling DNS queries signed with SIG(0). Using a specially-crafted DNS request, an attacker may be able to cause an ACL to improperly (mis)match an IP address. In a default-allow ACL (denying only specific IP addresses), this may lead to unauthorized access. Default-deny ACLs should fail-secure. This issue affects BIND 9 versions 9.20.0 through 9.20.20, 9.21.0 through 9.21.19, and 9.20.9-S1 through 9.20.20-S1. BIND 9 versions 9.1… | CVSS5.4v3.1 | EPSS0.36% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2026-3119MEDIUM | Authenticated query containing a TKEY record may cause named to terminate unexpectedlyUnder certain conditions, `named` may crash when processing a correctly signed query containing a TKEY record. The affected code can only be reached if an incoming request has a valid transaction signature (TSIG) from a key declared in the `named` configuration. This issue affects BIND 9 versions 9.20.0 through 9.20.20, 9.21.0 through 9.21.19, and 9.20.9-S1 through 9.20.20-S1. BIND 9 versions 9.18.0 through 9.18.46 and 9.18.11-S1 through 9.18.46-S1 are NOT affected. CWE-617Mar 25, 2026 | CVSS6.5v3.1 | EPSS0.576% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2026-3104HIGH | Memory leak in code preparing DNSSEC proofs of non-existenceA specially crafted domain can be used to cause a memory leak in a BIND resolver simply by querying this domain. This issue affects BIND 9 versions 9.20.0 through 9.20.20, 9.21.0 through 9.21.19, and 9.20.9-S1 through 9.20.20-S1. BIND 9 versions 9.18.0 through 9.18.46 and 9.18.11-S1 through 9.18.46-S1 are NOT affected. | CVSS7.5v3.1 | EPSS0.698% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2026-1519HIGH | Excessive NSEC3 iterations cause high CPU load during insecure delegation validationIf a BIND resolver is performing DNSSEC validation and encounters a maliciously crafted zone, the resolver may consume excessive CPU. Authoritative-only servers are generally unaffected, although there are circumstances where authoritative servers may make recursive queries (see: https://kb.isc.org/docs/why-does-my-authoritative-server-make-recursive-queries). This issue affects BIND 9 versions 9.11.0 through 9.16.50, 9.18.0 through 9.18.46, 9.20.0 through 9.20.20, 9.21.0 through 9.21.19, 9.11.3… | CVSS7.5v3.1 | EPSS1.6% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2025-13878HIGH | Malformed BRID/HHIT records can cause named to terminate unexpectedlyMalformed BRID/HHIT records can cause `named` to terminate unexpectedly. This issue affects BIND 9 versions 9.18.40 through 9.18.43, 9.20.13 through 9.20.17, 9.21.12 through 9.21.16, 9.18.40-S1 through 9.18.43-S1, and 9.20.13-S1 through 9.20.17-S1. | CVSS7.5v3.1 | EPSS8.22% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2025-40780HIGH | Cache poisoning due to weak PRNGIn specific circumstances, due to a weakness in the Pseudo Random Number Generator (PRNG) that is used, it is possible for an attacker to predict the source port and query ID that BIND will use. This issue affects BIND 9 versions 9.16.0 through 9.16.50, 9.18.0 through 9.18.39, 9.20.0 through 9.20.13, 9.21.0 through 9.21.12, 9.16.8-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.39-S1, and 9.20.9-S1 through 9.20.13-S1. CWE-341Oct 22, 2025 | CVSS8.6v3.1 | EPSS0.464% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2025-40778HIGH | Cache poisoning attacks with unsolicited RRsUnder certain circumstances, BIND is too lenient when accepting records from answers, allowing an attacker to inject forged data into the cache. This issue affects BIND 9 versions 9.11.0 through 9.16.50, 9.18.0 through 9.18.39, 9.20.0 through 9.20.13, 9.21.0 through 9.21.12, 9.11.3-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.39-S1, and 9.20.9-S1 through 9.20.13-S1. CWE-349Oct 22, 2025 | CVSS8.6v3.1 | EPSS0.665% | PoCs3 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2025-8677HIGH | Resource exhaustion via malformed DNSKEY handlingQuerying for records within a specially crafted zone containing certain malformed DNSKEY records can lead to CPU exhaustion. This issue affects BIND 9 versions 9.18.0 through 9.18.39, 9.20.0 through 9.20.13, 9.21.0 through 9.21.12, 9.18.11-S1 through 9.18.39-S1, and 9.20.9-S1 through 9.20.13-S1. CWE-405Oct 22, 2025 | CVSS7.5v3.1 | EPSS11.2% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2025-40777HIGH | A possible assertion failure when 'stale-answer-client-timeout' is set to '0'If a `named` caching resolver is configured with `serve-stale-enable` `yes`, and with `stale-answer-client-timeout` set to `0` (the only allowable value other than `disabled`), and if the resolver, in the process of resolving a query, encounters a CNAME chain involving a specific combination of cached or authoritative records, the daemon will abort with an assertion failure. This issue affects BIND 9 versions 9.20.0 through 9.20.10, 9.21.0 through 9.21.9, and 9.20.9-S1 through 9.20.10-S1. CWE-617Jul 16, 2025 | CVSS7.5v3.1 | EPSS0.877% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2025-40776HIGH | Birthday Attack against Resolvers supporting ECSA `named` caching resolver that is configured to send ECS (EDNS Client Subnet) options may be vulnerable to a cache-poisoning attack. This issue affects BIND 9 versions 9.11.3-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.37-S1, and 9.20.9-S1 through 9.20.10-S1. CWE-349Jul 16, 2025 | CVSS8.6v3.1 | EPSS0.197% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |