CVE-2026-17255

Received Received - Intake

Denial of Service in IBM i via ICMPv6 Router Advertisements

Publication date: 2026-09-04

Last updated on: 2026-09-04

Assigner: IBM Corporation

Description

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.

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-09-04

Last Modified

2026-09-04

Generated

2026-09-05

AI Q&A

2026-09-05

EPSS Evaluated

N/A

NVD

CVE-2026-17255

EUVD

EUVD-2026-71480

Affected Vendors & Products

Vendor	Product	Version / Range
ibm	i	7.6
ibm	i	7.5
ibm	i	7.4
ibm	i	7.3

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-787	The product writes data past the end, or before the beginning, of the intended buffer.

Attack-Flow Graph

Executive Summary

This vulnerability in IBM i 7.6, 7.5, 7.4, and 7.3 allows a remote attacker to cause a denial of service by sending improperly validated ICMPv6 Router Advertisements with incorrect prefix lengths.

Impact Analysis

The vulnerability could disrupt network services by causing the IBM i system to become unresponsive or crash due to the improper handling of malformed ICMPv6 Router Advertisements.

Mitigation Strategies

Apply IBM i PTFs or updates addressing ICMPv6 Router Advertisement validation. Monitor network traffic for unusual ICMPv6 Router Advertisements and restrict unnecessary ICMPv6 traffic at network boundaries.

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