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GrizzlyApplication · Eclipse

CVE-2026-12606

MEDIUM · 5.3 CVSS v3.1 Published 2026-07-14
Fix available
A fix is available. Upgrade to 5.0.2 or later.
See remediation →
62/100
Remediation priority · Elevated
Remotely reachable No privileges Zero-click 5 weeks old

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 · unedited
Eclipse Grizzly in versions before 5.0.2, cannot properly parse the trailer section in malformed trailer header's line, which can be leveraged to perform HTTP request smuggling. Grizzly 5.0.1 supports system properties that enable the behavior that fixes the vulnerability - set org.glassfish.grizzly.http.STRICT_HEADER_NAME_VALIDATION_RFC_9110 and org.glassfish.grizzly.http.STRICT_HEADER_VALUE_VALIDATION_RFC_9110 system properties to "true".

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 · high confidence

Eclipse Grizzly before version 5.0.2 fails to properly parse the trailer section in malformed trailer headers, enabling HTTP request smuggling attacks. This occurs because the parser cannot correctly handle malformed trailer header lines, allowing attackers to manipulate HTTP request boundaries.

MitigationUpgrade to Grizzly 5.0.2 or later, or set system properties org.glassfish.grizzly.http.STRICT_HEADER_NAME_VALIDATION_RFC_9110 and org.glassfish.grizzly.http.STRICT_HEADER_VALUE_VALIDATION_RFC_9110 to "true".

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
GrizzlyApplication
Affected:>= 4.0.0, <= 4.0.2>= 5.0.0, < 5.0.2

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
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify Eclipse Grizzly version
    Locate the grizzly-http-server JAR file in your application classpath or dependencies (typically in WEB-INF/lib, target/lib, or Maven/Gradle dependency tree). Check the filename or manifest for the version number.
    Affected if The installed version is 4.0.0 through 4.0.2, or 5.0.0 through 5.0.1 (any version prior to 5.0.2)
  2. Confirm HTTP trailer header processing is in use
    Search your application code, configuration files, and request/response logs for usage of HTTP trailer headers (look for 'Trailer' header in requests/responses, or programmatic use of Http Trailer API).
    Affected if The application processes HTTP requests containing trailer headers, as the vulnerability exploits malformed trailer parsing
  3. Check for upstream proxy or gateway configuration
    Examine if Grizzly is deployed behind a reverse proxy, load balancer, or API gateway that forwards HTTP requests to the Grizzly server.
    Affected if Requests pass through an upstream proxy or server before reaching Grizzly, as the flaw involves parsing inconsistency between Grizzly and such components
  4. Verify strict header validation is enabled
    Check if the Java system properties 'STRICT_HEADER_NAME_VALIDATION_RFC_9110' or 'STRICT_HEADER_VALUE_VALIDATION_RFC_9110' are set to 'true' in the JVM startup arguments or programmatically via System.setProperty.
    Affected if These mitigation properties are NOT set (the environment is relying on default lenient parsing)

You are affected if Grizzly version is prior to 5.0.2 and your application processes HTTP trailer headers from clients that may be routed through upstream proxies.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 · scoped
Upgrade available Upgrade to 5.0.2 or later
Fixed in 5.0.2
Interim mitigation

Upgrade to Grizzly 5.0.2 or later, or set system properties org.glassfish.grizzly.http.STRICT_HEADER_NAME_VALIDATION_RFC_9110 and org.glassfish.grizzly.http.STRICT_HEADER_VALUE_VALIDATION_RFC_9110 to "true".

Recommended fix High confidence

5.0.2

  1. 1. Identify the current Grizzly version in use by checking project dependencies (Maven pom.xml, Gradle build file, or bundled JAR version)
  2. 2. For Grizzly 5.0.0-5.0.1: Upgrade to version 5.0.2 or later which contains the complete fix
  3. 3. If upgrading to 5.0.2 is not immediately possible and using 5.0.1: Set JVM system properties `-Dorg.glassfish.grizzly.http.STRICT_HEADER_NAME_VALIDATION_RFC_9110=true` and `-Dorg.glassfish.grizzly.http.STRICT_HEADER_VALUE_VALIDATION_RFC_9110=true` to enable the mitigation
  4. 4. Verify the upgrade by running HTTP smuggling test cases to confirm the vulnerability is resolved
  5. 5. For Grizzly 4.x versions (4.0.0-4.0.2): There is no mentioned patch; consider upgrading to Grizzly 5.0.2 which is the supported branch with security fixes
Caveat Upgrading from Grizzly 4.x to 5.x may introduce API changes; review the Grizzly migration guide for compatibility impacts

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Grizzly Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,390
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-12606 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
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  • Version or environment caveats, and links to real fixes
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