Isc Bind 9 vulnerabilities

CVE-2019-6475 [HIGH] CWE-345 CVE-2019-6475: Mirror zones are a BIND feature allowing recursive servers to pre-cache zone data provided by other Mirror zones are a BIND feature allowing recursive servers to pre-cache zone data provided by other servers. A mirror zone is similar to a zone of type secondary, except that its data is subject to DNSSEC validation before being used in answers, as if it had been looked up via traditional recursion, and when mirror zone data cannot be validated, BIND fal

CVE-2026-11605 [HIGH] CWE-408 CVE-2026-11605: The issue is a resource exhaustion vulnerability associated with DNSSEC validation. BIND always vali The 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

CVE-2026-81736 [HIGH] CWE-1050 CVE-2026-81736: If a BIND resolver has cached a tree of SVCB/HTTPS AliasMode records, and is then queried for the ro If a BIND resolver has cached a tree of SVCB/HTTPS AliasMode records, and is then queried for the root of that tree, the resolver will spend disproportionate CPU time constructing the response. This issue affects BIND 9 versions 9.18.0 through 9.18.50, 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, 9.18.11-S1 through 9.18.50-S1, and 9.20.9-S1 throug

CVE-2026-76163 [HIGH] CWE-617 CVE-2026-76163: If BIND is loaded with a "`named.conf`" file that contains no global "`options`" block, an attacker If BIND is loaded with a "`named.conf`" file that contains no global "`options`" block, an attacker can send a query of QTYPE TKEY which may cause an assertion failure and subsequent unexpected program exit. This issue affects BIND 9 versions 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, and 9.20.9-S1 through 9.20.27-S1.

CVE-2026-96888 [HIGH] CWE-476 CVE-2026-96888: A BIND resolver that is configured with both a "redirect" zone and "qname-minimization strict" may a A BIND resolver that is configured with both a "redirect" zone and "qname-minimization strict" may abort with an assertion failure while processing the redirect. This issue affects BIND 9 versions 9.16.0 through 9.18.50, 9.20.0 through 9.20.29, 9.21.0 through 9.21.26, 9.16.8-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.29-S1.

CVE-2018-5734 [HIGH] CWE-617 CVE-2018-5734: While handling a particular type of malformed packet BIND erroneously selects a SERVFAIL rcode inste While handling a particular type of malformed packet BIND erroneously selects a SERVFAIL rcode instead of a FORMERR rcode. If the receiving view has the SERVFAIL cache feature enabled, this can trigger an assertion failure in badcache.c when the request doesn't contain all of the expected information. Affects BIND 9.10.5-S1 to 9.10.5-S4, 9.10.6-S1, 9.10

CVE-2018-5744 [HIGH] CWE-772 CVE-2018-5744: A failure to free memory can occur when processing messages having a specific combination of EDNS op A failure to free memory can occur when processing messages having a specific combination of EDNS options. Versions affected are: BIND 9.10.7 -> 9.10.8-P1, 9.11.3 -> 9.11.5-P1, 9.12.0 -> 9.12.3-P1, and versions 9.10.7-S1 -> 9.11.5-S3 of BIND 9 Supported Preview Edition. Versions 9.13.0 -> 9.13.6 of the 9.13 development branch are also affected.

CVE-2023-2911 [HIGH] CWE-787 CVE-2023-2911: If the `recursive-clients` quota is reached on a BIND 9 resolver configured with both `stale-answer- If the `recursive-clients` quota is reached on a BIND 9 resolver configured with both `stale-answer-enable yes;` and `stale-answer-client-timeout 0;`, a sequence of serve-stale-related lookups could cause `named` to loop and terminate unexpectedly due to a stack overflow. This issue affects BIND 9 versions 9.16.33 through 9.16.41, 9.18.7 through 9.18.15

CVE-2023-4236 [HIGH] CWE-617 CVE-2023-4236: A flaw in the networking code handling DNS-over-TLS queries may cause `named` to terminate unexpecte A flaw in the networking code handling DNS-over-TLS queries may cause `named` to terminate unexpectedly due to an assertion failure. This happens when internal data structures are incorrectly reused under significant DNS-over-TLS query load. This issue affects BIND 9 versions 9.18.0 through 9.18.18 and 9.18.11-S1 through 9.18.18-S1.

CVE-2023-4408 [HIGH] CWE-407 CVE-2023-4408: The DNS message parsing code in `named` includes a section whose computational complexity is overly The DNS message parsing code in `named` includes a section whose computational complexity is overly high. It does not cause problems for typical DNS traffic, but crafted queries and responses may cause excessive CPU load on the affected `named` instance by exploiting this flaw. This issue affects both authoritative servers and recursive resolvers. This i

CVE-2017-3135 [MEDIUM] CWE-476 CVE-2017-3135: Under some conditions when using both DNS64 and RPZ to rewrite query responses, query processing can Under some conditions when using both DNS64 and RPZ to rewrite query responses, query processing can resume in an inconsistent state leading to either an INSIST assertion failure or an attempt to read through a NULL pointer. Affects BIND 9.8.8, 9.9.3-S1 -> 9.9.9-S7, 9.9.3 -> 9.9.9-P5, 9.9.10b1, 9.10.0 -> 9.10.4-P5, 9.10.5b1, 9.11.0 -> 9.11.0-P2, 9.11.

CVE-2026-81563 [HIGH] CWE-401 CVE-2026-81563: A BIND resolver encountering an SVCB/HTTPS AliasMode record referencing 14 or more SVCB/HTTPS Servic A BIND resolver encountering an SVCB/HTTPS AliasMode record referencing 14 or more SVCB/HTTPS ServiceMode records may fail to properly deallocate internal resources. If this happens repeatedly, resource exhaustion will eventually prevent the resolver from performing new recursive lookups. This issue affects BIND 9 versions 9.18.0 through 9.18.50, 9.20

CVE-2026-19667 [HIGH] CWE-197 CVE-2026-19667: If an attacker-controlled authoritative server can produce a negative answer that is exactly 65536 b If an attacker-controlled authoritative server can produce a negative answer that is exactly 65536 bytes, then a flaw in `named` results in a negative cache entry of 0 bytes. When this entry is subsequently read, `named` aborts. This issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, 9.11.3-S1 through

CVE-2026-12617 [HIGH] CWE-617 CVE-2026-12617: The issue is unexpected program termination based on ordering and/or specific content in responses t The 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 neg

CVE-2026-13204 [HIGH] CWE-617 CVE-2026-13204: If a provably insecure domain is covered by both an NSEC and NSEC3 record at the parent, and there e If 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 9.18.5

CVE-2026-19630 [HIGH] CWE-407 CVE-2026-19630: In a BIND resolver, inbound DNS protocol messages with a particular structure will result in additio In a BIND resolver, inbound DNS protocol messages with a particular structure will result in additional processing, with no limit imposed by BIND. A DNS message with a maliciously large number of such structures will cause BIND to consume disproportionate amounts of CPU time and memory during processing. This issue affects BIND 9 versions 9.11.0 throu

CVE-2023-5517 [HIGH] CWE-617 CVE-2023-5517: A flaw in query-handling code can cause `named` to exit prematurely with an assertion failure when: A flaw in query-handling code can cause `named` to exit prematurely with an assertion failure when: - `nxdomain-redirect ;` is configured, and - the resolver receives a PTR query for an RFC 1918 address that would normally result in an authoritative NXDOMAIN response. This issue affects BIND 9 versions 9.12.0 through 9.16.45, 9.18.0 through 9.18.21, 9.1

CVE-2025-40777 [HIGH] CWE-617 CVE-2025-40777: If a `named` caching resolver is configured with `serve-stale-enable` `yes`, and with `stale-answer- 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 wi

CVE-2023-5679 [HIGH] CWE-617 CVE-2023-5679: A bad interaction between DNS64 and serve-stale may cause `named` to crash with an assertion failure A bad interaction between DNS64 and serve-stale may cause `named` to crash with an assertion failure during recursive resolution, when both of these features are enabled. This issue affects BIND 9 versions 9.16.12 through 9.16.45, 9.18.0 through 9.18.21, 9.19.0 through 9.19.19, 9.16.12-S1 through 9.16.45-S1, and 9.18.11-S1 through 9.18.21-S1.

CVE-2023-2829 [HIGH] CVE-2023-2829: A `named` instance configured to run as a DNSSEC-validating recursive resolver with the Aggressive U A `named` instance configured to run as a DNSSEC-validating recursive resolver with the Aggressive Use of DNSSEC-Validated Cache (RFC 8198) option (`synth-from-dnssec`) enabled can be remotely terminated using a zone with a malformed NSEC record. This issue affects BIND 9 versions 9.16.8-S1 through 9.16.41-S1 and 9.18.11-S1 through 9.18.15-S1.