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Openj9Application · Eclipse

CVE-2026-16439

CRITICAL · 9.1 CVSS v3.1 Published 2026-07-21
Fix available
A fix is available. Upgrade to 0.60.0 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click 4 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
In Eclipse OpenJ9 versions up to 0.60, using -Xtrace to trace method arguments can lead to buffer underflow.

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 confidence

A buffer underflow vulnerability exists in Eclipse OpenJ9's -Xtrace tracing functionality when tracing method arguments. The issue occurs due to insufficient bounds checking in the trace formatting code for method arguments, allowing read operations before the start of a buffer. This could potentially allow an attacker to read sensitive memory contents or cause a crash.

MitigationUpgrade to a patched version of OpenJ9 beyond 0.60. If upgrading is not immediately feasible, disable or restrict use of the -Xtrace option, particularly with methods that trace method arguments, to reduce the attack surface.

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
Openj9Application
Affected:>= 0.8.0, < 0.60.0

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
High
Availability
High

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

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

  1. Identify if OpenJ9 JVM is in use
    Run 'java -version' and check if the output contains 'Eclipse OpenJ9' or 'OpenJ9'. Standard Oracle/HotSpot JVMs are not affected.
    Affected if The output does NOT contain 'Eclipse OpenJ9' or 'OpenJ9' - the system uses a different JVM implementation.
  2. Determine the installed OpenJ9 version
    Run 'java -version -XshowSettings:all 2>&1' or 'java -XshowSettings:version -version' and locate the version string in the output (typically shown as 'openj9.version' or in the java -version output line).
    Affected if The version is 0.8.0 or higher but lower than 0.60.0 (for example, 0.45.0, 0.50.0, 0.59.0). Versions 0.60.0 and above are patched.
  3. Check for active -Xtrace tracing option
    Review the Java process command line or startup scripts for '-Xtrace' flag usage. Also check for any active trace configuration files if the JVM was started with persistent trace settings.
    Affected if The -Xtrace option is present in the JVM command line arguments or active configuration.
  4. Check if method argument tracing is enabled
    Examine the -Xtrace parameters for patterns that indicate method argument tracing, such as 'methods=...' or 'argtrace' or similar method tracing specifications in the trace configuration.
    Affected if Method argument tracing (capturing method arguments) is explicitly enabled via the -Xtrace options.

The environment is affected only if running a vulnerable OpenJ9 version (0.8.0 to less than 0.60.0) AND the -Xtrace option with method argument tracing is actively in use.

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 0.60.0 or later
Fixed in 0.60.0
Interim mitigation

Upgrade to a patched version of OpenJ9 beyond 0.60. If upgrading is not immediately feasible, disable or restrict use of the -Xtrace option, particularly with methods that trace method arguments, to reduce the attack surface.

Recommended fix Moderate confidence

Eclipse OpenJ9 version 0.61 or later

  1. 1. Identify the current Eclipse OpenJ9 version in use by running: java -version
  2. 2. Upgrade Eclipse OpenJ9 to a version newer than 0.60 (e.g., 0.61 or later) that contains the fix for the buffer underflow vulnerability
  3. 3. Verify the upgrade was successful by running: java -version
  4. 4. Test any applications that rely on -Xtrace tracing functionality to ensure compatibility with the upgraded version
  5. 5. If upgrading is not immediately possible, avoid using -Xtrace with method argument tracing as a temporary mitigation
Caveat Users relying on specific -Xtrace behavior in versions up to 0.60 should test their tracing configurations after upgrading

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

Fix this in Openj9 Scoped from the published advisory
  • Consultation8.0 h
  • Implementation16.0 h
  • Testing12.0 h
  • Review / QA8.0 h
44.0 hours of engineering $7,720
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $12,352.

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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-2026-16439 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
  • 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
  • No spam, self-promotion, credentials, or personal data