{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","feed_url":"https://feed.craftedsignal.io/products/bind-9-9.11.3-s1-through-9.18.50-s1/feed.json","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[{"cvss":8.6,"id":"CVE-2026-13321"}],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["BIND 9 (9.11.0 through 9.18.50)","BIND 9 (9.20.0 through 9.20.24)","BIND 9 (9.21.0 through 9.21.23)","BIND 9 (9.11.3-S1 through 9.18.50-S1)","BIND 9 (9.20.9-S1 through 9.20.24-S1)"],"_cs_severities":["high"],"_cs_tags":["vulnerability","dns","bind"],"_cs_type":"advisory","_cs_vendors":["Internet Systems Consortium"],"content_html":"\u003cp\u003eCVE-2026-13321, identified by the Internet Systems Consortium (ISC), details an origin validation error (CWE-346) in the BIND 9 DNS resolver. This vulnerability allows the resolver to accept validly-signed NSEC records even when their \u0026quot;Next Domain Name\u0026quot; field references a domain name outside the signer's designated zone. This critical flaw has a CVSSv3.1 base score of 8.6, indicating a high impact on integrity. The issue affects a wide range of BIND 9 versions, including 9.11.0 through 9.18.50, 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, and their corresponding -S1 series. Organizations operating affected BIND resolvers are at risk of DNS cache poisoning or other DNS-based attacks due to improper validation of DNSSEC records. The vulnerability enables an attacker to manipulate DNS resolution, potentially leading to redirection to malicious servers or interception of network traffic.\u003c/p\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of CVE-2026-13321 could lead to significant integrity compromises within organizations reliant on vulnerable BIND resolvers. The high integrity impact (I:H) indicated by the CVSS score suggests that an attacker could inject malicious or incorrect data into the DNS cache. This cache poisoning could enable DNS spoofing, where users are redirected to attacker-controlled websites instead of legitimate ones. Such redirection can facilitate phishing attacks, credential harvesting, or the delivery of malware. Organizations, regardless of sector, that use affected BIND versions for DNS resolution are vulnerable to these attacks, potentially leading to data breaches, service disruptions, and reputational damage.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eImmediately update all affected BIND 9 installations to patched versions available from ISC to remediate CVE-2026-13321. Specifically, update BIND 9.18.50 to 9.18.51, 9.20.24 to 9.20.26, and 9.21.23 to 9.21.24 or newer as referenced in the ISC advisory.\u003c/li\u003e\n\u003cli\u003eRegularly monitor DNS query and response logs for anomalies, especially around NSEC records or unexpected domain resolutions, to detect potential exploitation attempts.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-07-22T15:24:36Z","date_published":"2026-07-22T15:24:36Z","id":"https://feed.craftedsignal.io/briefs/2026-07-cve-2026-13321-bind-nsec-vulnerability/","summary":"CVE-2026-13321 describes a vulnerability in the BIND resolver where it incorrectly accepts validly-signed NSEC records that contain a 'Next Domain Name' field pointing outside the signer's zone, impacting integrity with a CVSSv3.1 score of 8.6 and requiring immediate updates to affected BIND 9 installations.","title":"CVE-2026-13321 BIND Resolver Origin Validation Error","url":"https://feed.craftedsignal.io/briefs/2026-07-cve-2026-13321-bind-nsec-vulnerability/"},{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[{"cvss":7.5,"id":"CVE-2026-13204"}],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["BIND 9 (9.11.0 through 9.18.50)","BIND 9 (9.20.0 through 9.20.24)","BIND 9 (9.21.0 through 9.21.23)","BIND 9 (9.11.3-S1 through 9.18.50-S1)","BIND 9 (9.20.9-S1 through 9.20.24-S1)"],"_cs_severities":["low"],"_cs_tags":["dns","dos","vulnerability","bind","cve"],"_cs_type":"advisory","_cs_vendors":["Internet Systems Consortium (ISC)"],"content_html":"\u003cp\u003eA high-severity denial-of-service vulnerability, identified as CVE-2026-13204, has been discovered in multiple versions of Internet Systems Consortium (ISC) BIND 9. This flaw exists in the DNSSEC validation logic. Specifically, if a DNS resolver running a vulnerable BIND 9 version attempts to validate a provably insecure domain where the parent zone provides both NSEC (Next Secure) and NSEC3 (NSEC version 3) records, but an RRSIG (Resource Record Signature) exists for only one of these types, the BIND process may terminate unexpectedly. This assertion failure effectively causes a denial of service for the affected BIND server, disrupting DNS resolution for its clients. The vulnerability 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, and specific extended support versions.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eAn attacker controls an authoritative DNS server for a malicious domain.\u003c/li\u003e\n\u003cli\u003eThe attacker configures their authoritative server to serve the parent zone of the malicious domain with both NSEC and NSEC3 records.\u003c/li\u003e\n\u003cli\u003eThe attacker deliberately ensures that an RRSIG (DNSSEC signature) is present for only one of these record types (either NSEC or NSEC3), but not both, for the malicious domain's non-existent records.\u003c/li\u003e\n\u003cli\u003eA vulnerable BIND 9 DNS resolver attempts to validate a query for a non-existent record within this malicious domain.\u003c/li\u003e\n\u003cli\u003eDuring DNSSEC validation, the BIND resolver attempts to process the insecure domain's NSEC and NSEC3 records and their RRSIGs as provided by the attacker-controlled authoritative server.\u003c/li\u003e\n\u003cli\u003eDue to the specific and malformed configuration (presence of both NSEC/NSEC3 records with an RRSIG for only one), the BIND resolver encounters an assertion failure within its validation logic.\u003c/li\u003e\n\u003cli\u003eThe BIND 9 server process exits unexpectedly, leading to a denial of service for all DNS resolution requests that it handles.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of CVE-2026-13204 leads to a complete denial of service for the affected BIND 9 DNS resolver. This can prevent users and systems reliant on the compromised resolver from accessing internet resources, causing significant operational disruption. With a CVSS v3.1 Base Score of 7.5 (High), this vulnerability poses a severe risk to organizations running vulnerable BIND 9 instances. The impact is network-wide, as DNS is a fundamental service for internet communication. Any organization utilizing affected BIND 9 versions for their DNS infrastructure is at risk.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003ePrioritize patching all affected BIND 9 instances to a fixed version as soon as possible, referencing the security advisories linked in this brief. Specific 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 are affected.\u003c/li\u003e\n\u003cli\u003eMonitor BIND 9 server logs for unexpected process terminations or assertion failures, which may indicate attempted exploitation of CVE-2026-13204.\u003c/li\u003e\n\u003cli\u003eEnsure robust monitoring and alerting for DNS service availability to quickly detect and respond to potential denial-of-service events on BIND 9 servers.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-07-22T15:23:36Z","date_published":"2026-07-22T15:23:36Z","id":"https://feed.craftedsignal.io/briefs/2026-07-cve-2026-13204-bind-dos/","summary":"A critical vulnerability (CVE-2026-13204) in Internet Systems Consortium (ISC) BIND 9 can lead to a denial-of-service condition where the server exits unexpectedly due to an assertion failure during DNSSEC validation of specific NSEC/NSEC3 record configurations. This allows an unauthenticated attacker to cause a BIND 9 DNS resolver to crash, disrupting DNS resolution services.","title":"CVE-2026-13204: BIND 9 Denial-of-Service Vulnerability","url":"https://feed.craftedsignal.io/briefs/2026-07-cve-2026-13204-bind-dos/"},{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[{"cvss":7.5,"id":"CVE-2026-11622"}],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["BIND 9 (9.11.0 through 9.18.50)","BIND 9 (9.20.0 through 9.20.24)","BIND 9 (9.21.0 through 9.21.23)","BIND 9 (9.11.3-S1 through 9.18.50-S1)","BIND 9 (9.20.9-S1 through 9.20.24-S1)"],"_cs_severities":["high"],"_cs_tags":["dns","denial-of-service","vulnerability","isc","bind","cache-poisoning","network"],"_cs_type":"advisory","_cs_vendors":["ISC"],"content_html":"\u003cp\u003eCVE-2026-11622 details a critical vulnerability affecting multiple versions of ISC BIND 9, a widely used DNS software. This flaw impacts DNSSEC validating resolvers, allowing an unauthenticated attacker to trigger a denial-of-service (DoS) condition. The attack involves initiating a \u0026quot;random subdomain attack\u0026quot; against a DNSSEC-signed zone. By sending a high volume of queries for non-existent, random subdomains, the attacker can force the resolver to consume excessive memory. The vulnerability specifically targets BIND 9 versions from 9.11.0 through 9.18.50, 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, and their respective S1 branches (9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.24-S1). This uncontrolled memory growth can occur even when \u003ccode\u003emax-cache-size\u003c/code\u003e limits are configured, rendering the resolver unresponsive and disrupting critical DNS resolution services.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eAn attacker identifies a target BIND 9 DNSSEC validating resolver and a DNSSEC-signed zone that the resolver can query.\u003c/li\u003e\n\u003cli\u003eThe attacker initiates a flood of DNS queries for non-existent, random subdomains (e.g., \u003ccode\u003erandomstring.example.com\u003c/code\u003e) within the chosen DNSSEC-signed zone.\u003c/li\u003e\n\u003cli\u003eThe vulnerable BIND 9 resolver attempts to validate each unique non-existent subdomain query, a process that is computationally intensive for DNSSEC.\u003c/li\u003e\n\u003cli\u003eThe rate at which the attacker sends queries for new, random subdomains exceeds the resolver's capacity to complete DNSSEC validation for each request.\u003c/li\u003e\n\u003cli\u003eAs the resolver's cache attempts to store validation states for numerous unique, non-existent entries, its memory usage begins to increase rapidly.\u003c/li\u003e\n\u003cli\u003eThe memory consumption escalates significantly, potentially by orders of magnitude beyond any configured \u003ccode\u003emax-cache-size\u003c/code\u003e parameter due to the nature of DNSSEC validation state storage.\u003c/li\u003e\n\u003cli\u003eThe BIND 9 process exhausts available memory resources, leading to a crash or severe performance degradation, effectively causing a denial-of-service condition for all DNS queries.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of CVE-2026-11622 leads to a complete denial-of-service for affected BIND 9 DNSSEC validating resolvers. This means that organizations relying on these resolvers will experience service outages for DNS resolution, preventing access to internal and external resources that depend on DNS. The impact can be severe for internet service providers, enterprises, and other entities running vulnerable BIND instances, causing widespread network disruptions and unavailability of critical applications. The memory exhaustion can persist even with cache size limits, making manual intervention necessary to restore service.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003ePatch CVE-2026-11622 on all affected BIND 9 instances immediately by upgrading to a version where the vulnerability is resolved. Consult ISC advisories for specific patched versions.\u003c/li\u003e\n\u003cli\u003eMonitor DNS server resource utilization (CPU, memory, network I/O) for anomalies. Sudden spikes in memory usage on BIND 9 servers could indicate an attempted or ongoing exploitation of CVE-2026-11622.\u003c/li\u003e\n\u003cli\u003eImplement rate limiting on incoming DNS queries where feasible to mitigate the impact of high-volume attacks, though this may not fully prevent memory exhaustion for CVE-2026-11622.\u003c/li\u003e\n\u003cli\u003eReview DNS query logs for unusual patterns, such as a high volume of queries for random, non-existent subdomains from a single source or a small set of sources, which could indicate a random subdomain attack.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-07-22T15:22:02Z","date_published":"2026-07-22T15:20:51Z","id":"https://feed.craftedsignal.io/briefs/2026-07-cve-2026-11622-dnssec-memory-dos/","summary":"A DNSSEC validating resolver, specifically BIND 9 versions within the ranges 9.11.0-9.18.50, 9.20.0-9.20.24, 9.21.0-9.21.23, and their S1 variants, is vulnerable to a denial-of-service attack where an attacker can launch a random subdomain attack against a DNSSEC-signed zone by sending queries faster than the resolver can perform validation, leading to runaway memory usage and potentially exceeding configured limits by orders of magnitude.","title":"CVE-2026-11622: BIND 9 DNSSEC Resolver Memory Exhaustion Vulnerability","url":"https://feed.craftedsignal.io/briefs/2026-07-cve-2026-11622-dnssec-memory-dos/"}],"language":"en","title":"CraftedSignal Threat Feed - BIND 9 (9.11.3-S1 Through 9.18.50-S1)","version":"https://jsonfeed.org/version/1.1"}