CVE-2026-17255: IBM i is Affected By Denial of Service Vulnerability []

Q: What access does an attacker need to exploit this issue?

The attacker needs network access to send crafted ICMPv6 Router Advertisements to the affected IBM i system. No privileges or user interaction are required.

Q: What is the expected impact of successful exploitation?

Successful exploitation can cause a denial of service. The provided information does not indicate confidentiality or integrity impact.

Q: Which IBM i releases are identified as affected?

IBM i 7.3, 7.4, 7.5, and 7.6 are identified as affected.

Published Sep 2, 2026

Updated

IBM i 7.6, 7.5, 7.4, and 7.3 could allow a remote attacker to cause a denial of service due to improper validation of the prefix length in ICMPv6 Router Advertisements.

Other sources

IBM i could allow a remote attacker to cause a denial of service due to improper validation of the prefix length in ICMPv6 Router Advertisements.

— IBM

Affected Software

5 affected components

IBM i>7.3<=7.6

IBM i<=7.6

IBM i<=7.5

IBM i<=7.4

IBM i<=7.3

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade IBM i to a version that resolves this vulnerability.
Fixed in 7.6Patch MJ11322
Upgrade
Upgrade IBM i to a version that resolves this vulnerability.
Fixed in 7.5Patch MJ11323
Upgrade
Upgrade IBM i to a version that resolves this vulnerability.
Fixed in 7.4Patch MJ11324
Upgrade
Upgrade IBM i to a version that resolves this vulnerability.
Fixed in 7.3Patch MJ11325

Event History

Sep 2, 2026

CVE Published

via IBM·12:00 AM

Data Sourced

via IBM·12:00 AM

DescriptionAffected Software

Sep 4, 2026

CVE Published

via MITRE·04:39 PM

Data Sourced

via MITRE·04:39 PM

RemedyDescriptionSeverityWeakness

Data Sourced

via NVD·05:16 PM

DescriptionSeverityWeakness

Parent advisories

This vulnerability appears in the following advisories.

IBM-7286093

Frequently Asked Questions

What access does an attacker need to exploit this issue?

The attacker needs network access to send crafted ICMPv6 Router Advertisements to the affected IBM i system. No privileges or user interaction are required.

What is the expected impact of successful exploitation?

Successful exploitation can cause a denial of service. The provided information does not indicate confidentiality or integrity impact.

Which IBM i releases are identified as affected?

IBM i 7.3, 7.4, 7.5, and 7.6 are identified as affected.

CVE-2026-17255: IBM i is Affected By Denial of Service Vulnerability []

Other sources

Affected Software

Remediation

Event History

Parent advisories

Frequently Asked Questions

What access does an attacker need to exploit this issue?

What is the expected impact of successful exploitation?

Which IBM i releases are identified as affected?

Company

Resources

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