Buffer Overflow in IBM i JSSE Provider Affects Multiple Versions
CVE-2026-18511

7.3HIGH

Key Information:

Vendor

IBM
Status
I
Vendor
CVE Published:
13 August 2026

What is CVE-2026-18511?

The Native IBM i JSSE provider is vulnerable to a stack-based buffer overflow due to inadequate bounds checking during the establishment of TLS sessions. This vulnerability allows a local authenticated attacker to overflow a fixed-length buffer, potentially executing arbitrary code on the system or causing a crash of the Java Virtual Machine (JVM) process. It is essential for administrators to apply patches and monitor their systems to mitigate the risks associated with this vulnerability.

Affected Version(s)

i 7.6

i 7.5

i 7.4

References

https://www.ibm.com/support/pages/node/7283285
vendor-advisorypatch

CVSS V3.1

Score:
7.3
Severity:
HIGH
Confidentiality:
Low
Integrity:
Low
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.