Out-of-bounds Read in Eclipse Openj9

CVE-2026-6918

In Eclipse Open9J versions 0.21 to 0.58, a pre-authentication remote attacker can crash JITServer by sending a 32-byte crafted TCP message.

Vulnerability class: Buffer Overflow

EPSS: 0.001 (18.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Eclipse Openj9
Eclipse Foundation Openj9 — versions 0.21

Weakness classification (CWE)

CWE-125 — Out-of-bounds Read

References

emo@eclipse.org (Patch, Issue Tracking)
emo@eclipse.org (Exploit, Vendor Advisory)

Frequently asked questions

What is CVE-2026-6918?: CVE-2026-6918 is a high-severity vulnerability in Eclipse Openj9, classified under Out-of-bounds Read. CVSS score: 7.5/10. Published 2026-05-05.
How severe is CVE-2026-6918?: High severity. CVSS v3 base score is 7.5 out of 10.