Summary
hickory-resolver follows irrelevant CNAME records
When the Hickory DNS resolver follows CNAME records, it sends queries that are not necessary to answer the original recursive query. If there are any CNAME records in the authority section or additional section of the response, queries will be sent for those names. If there are any CNAME records that are not part of a CNAME chain starting from the original recursive query name, queries will be sent for those names. This increases query amplification beyond what is necessary to answer the recursive query.
Impact
Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service. Typical impact: denial of service.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is GHSA-6F2X-V7Q7-M7M5? GHSA-6F2X-V7Q7-M7M5 is a medium-severity uncontrolled resource consumption vulnerability in hickory-resolver (rust), affecting versions >= 0.25.0, < 0.26.2. It is fixed in 0.26.2. Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service.
- Which versions of hickory-resolver are affected by GHSA-6F2X-V7Q7-M7M5? hickory-resolver (rust) versions >= 0.25.0, < 0.26.2 is affected.
- Is there a fix for GHSA-6F2X-V7Q7-M7M5? Yes. GHSA-6F2X-V7Q7-M7M5 is fixed in 0.26.2. Upgrade to this version or later.
- Is GHSA-6F2X-V7Q7-M7M5 exploitable, and should I be worried? Whether GHSA-6F2X-V7Q7-M7M5 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether GHSA-6F2X-V7Q7-M7M5 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix GHSA-6F2X-V7Q7-M7M5? Upgrade
hickory-resolverto 0.26.2 or later.