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HIGH · 7.3

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 sessi...

Vulnerability Description

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.

CVSS Score

7.3

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
LOW
Availability
LOW

Affected Products

VendorProductVersions
IbmI7.3

Related Weaknesses (CWE)

CWE-787

References

FAQ

What is CVE-2026-18511?

CVE-2026-18511 is a vulnerability with a CVSS score of 7.3 (HIGH). 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 sessi...

How severe is CVE-2026-18511?

CVE-2026-18511 has been rated HIGH with a CVSS base score of 7.3/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-18511?

Check the references section above for vendor advisories and patch information. Affected products include: Ibm I.