CVE-2026-18020: IBM i is Affected By Multiple Vulnerabilities in NetServer
IBM i 7.6, 7.5, 7.4, and 7.3 could allow a remote attacker to cause a denial of service due to an off-by-one error in bounds checking.
Other sources
IBM i could allow a remote attacker to cause a denial of service due to an off-by-one error in bounds checking.
— IBM
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
IBM i (Release5770-999)to a version that resolves this vulnerability.Fixed in 7.6Patch MJ10939 - Upgrade
Upgrade
IBM i (Release5770-999)to a version that resolves this vulnerability.Fixed in 7.5Patch MJ10938 - Upgrade
Upgrade
IBM i (Release5770-999)to a version that resolves this vulnerability.Fixed in 7.4Patch MJ10937 - Upgrade
Upgrade
IBM i (Release5770-999)to a version that resolves this vulnerability.Fixed in 7.3Patch MJ10936
Event History
Frequently Asked Questions
What is the severity of CVE-2026-18020?
The severity of CVE-2026-18020 is rated as medium with a score of 5.3.
What vulnerabilities does CVE-2026-18020 address?
CVE-2026-18020 addresses multiple vulnerabilities in IBM i's NetServer, enabling potential denial of service due to an off-by-one error in bounds checking.
How do I fix CVE-2026-18020?
To fix CVE-2026-18020, apply the latest security patches provided by IBM for IBM i versions 7.3, 7.4, 7.5, and 7.6.
Which versions of IBM i are affected by CVE-2026-18020?
CVE-2026-18020 affects IBM i versions 7.3, 7.4, 7.5, and 7.6.
What impact does CVE-2026-18020 have on IBM i systems?
CVE-2026-18020 can allow a remote attacker to cause a denial of service on vulnerable IBM i systems.