Buffer overflow in Ibm I

CVE-2026-18511

IBM i 7.6, 7.5, 7.4, and 7.3 could allow a local authenticated attacker to generate a stack-based buffer overflow in the Native IBM i JSSE provider, caused by improper bounds checking during TLS session establishment. A local attacker could overflow a fixed-length buffer and execute arbitrary code on the system or cause the JVM process to crash.

Vulnerability class: Buffer Overflow

CVSS v3 metric

CVSS v3 base score 7.3 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L.

Affected products

  • Ibm I — versions 7.6, 7.5, 7.4

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-18511?
CVE-2026-18511 is a high-severity vulnerability in Ibm I, classified under Out-of-bounds Write. CVSS score: 7.3/10. Published 2026-08-13.
How severe is CVE-2026-18511?
High severity. CVSS v3 base score is 7.3 out of 10.