CVE-2026-40984
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedIn Micrometer, it is possible for a user to provide specially crafted HTTP requests that may cause a denial-of-service (DoS) condition. Affected versions: micrometer-core 1.16.0 through 1.16.5; 1.15.0 through 1.15.11; 1.14.0 through 1.14.15; 1.13.0 through 1.13.18; 1.9.0 through 1.9.17. micrometer-jetty11 1.16.0 through 1.16.5; 1.15.0 through 1.15.11; 1.14.0 through 1.14.15; 1.13.0 through 1.13.18. micrometer-jetty12 1.16.0 through 1.16.5; 1.15.0 through 1.15.11; 1.14.0 through 1.14.15; 1.13.0 through 1.13.18.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceMicrometer, a metrics/monitoring library for Java applications, contains a denial-of-service vulnerability where specially crafted HTTP requests can trigger a DoS condition. The vulnerability affects both the core library and Jetty integration modules (jetty11, jetty12) across versions 1.9.0 through 1.16.5.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify Micrometer dependencyReview your project's dependency management (Maven pom.xml, Gradle build.gradle, or similar) for the micrometer-core or micrometer-registry-jetty dependency and note its version.Affected if The micrometer dependency version is older than 1.16.6, 1.15.12, 1.14.16, 1.13.19, or 1.9.18 (or if version cannot be determined but Micrometer is present).
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Confirm Jetty 11 or 12 integration is in useCheck if your application uses micrometer-jetty11 or micrometer-jetty12 (or micrometer-jetty with Jetty 11/12 server). This can be verified by examining classpath, dependencies, or runtime environment.Affected if Micrometer with Jetty 11 or Jetty 12 integration is present.
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Verify metrics HTTP endpoints are exposedInspect your application configuration for metrics endpoints enabled via micrometer's Jetty server. Typically, check for properties like management.endpoints.web.exposure.include=metrics or similar endpoint configuration, or confirm the application exposes /metrics or /prometheus endpoints on an accessible port.Affected if HTTP metrics endpoints are exposed and accessible (either on a public interface or without authentication).
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Check for unusual HTTP traffic patternsReview HTTP access logs for your application's metrics endpoints (typically /metrics, /prometheus, or /health) for sudden spikes in requests, abnormally large request headers, or rapid repeated requests from single sources.Affected if You observe excessive request volume targeting metrics endpoints that correlates with service degradation or resource exhaustion.
You are affected if your Micrometer version is below the fixed versions (1.16.6+, 1.15.12+, 1.14.16+, 1.13.19+, or 1.9.18+) AND you use the Jetty 11/12 integration with exposed HTTP metrics endpoints.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scopedUpgrade to patched versions of micrometer-core, micrometer-jetty11, and micrometer-jetty12 as specified in the security advisory. Implement request size limits and rate limiting on exposed actuator/metrics endpoints as a temporary mitigation.
Upgrade to micrometer-core/jetty11/jetty12 version 1.13.19+, 1.14.16+, 1.15.12+, or 1.16.6+ (choose the appropriate minor version branch)
- Identify the micrometer library version in use by examining project dependencies (pom.xml, build.gradle, or similar)
- For micrometer-core: upgrade to version 1.13.19 or later for the 1.13 branch, 1.14.16 or later for the 1.14 branch, 1.15.12 or later for the 1.15 branch, or 1.16.6 or later for the 1.16 branch
- For micrometer-jetty11: upgrade to version 1.13.19 or later for the 1.13 branch, 1.14.16 or later for the 1.14 branch, 1.15.12 or later for the 1.15 branch, or 1.16.6 or later for the 1.16 branch
- For micrometer-jetty12: upgrade to version 1.13.19 or later for the 1.13 branch, 1.14.16 or later for the 1.14 branch, 1.15.12 or later for the 1.15 branch, or 1.16.6 or later for the 1.16 branch
- Update dependency management files with the new version(s)
- Rebuild and redeploy the application
- Verify the application starts successfully and test the affected functionality
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-40984 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-40984 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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