CVE-2026-18511: IBM i is Affected By Multiple Vulnerabilities in Java Secure Sockets Extension
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.
Other sources
IBM i 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.
— IBM
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 7.6
Event History
Frequently Asked Questions
What is the severity of CVE-2026-18511?
The severity of CVE-2026-18511 is high with a score of 7.3.
How do I fix CVE-2026-18511?
To fix CVE-2026-18511, ensure that you update your IBM i systems to the latest version provided by IBM that addresses this vulnerability.
What systems are affected by CVE-2026-18511?
CVE-2026-18511 affects IBM i versions 7.6, 7.5, 7.4, and 7.3.
What type of vulnerability is CVE-2026-18511?
CVE-2026-18511 is a buffer overflow vulnerability related to the Java Secure Sockets Extension in IBM i.
Who can exploit CVE-2026-18511?
CVE-2026-18511 can be exploited by a local authenticated attacker to potentially execute arbitrary code.