Reference page — cumulative record through Sunday, October 4, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-17255

CVE-2026-17255HIGH

IBM i is Affected By Denial of Service Vulnerability []

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   N   N  U  N  N  H    7.5   .0040   32.4     —

AFFECTED
  Product  Versions  Fixed
  i        7.6 –     —

TIMELINE
  Jul 24  Reserved by ibm
  Sep 4   Published (CNA: ibm)
  Sep 8   RESCORED — CVE-2026-17255 (IBM i). CVSS 4.3 → 7.5 (NVD).

CWE-787 · CNA: ibm · CVSS v3.1 · 1 reference · NVD status: Analyzed

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.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
July 24, 2026	Reserved	Reserved by ibm
September 4, 2026	Published	Published (CNA: ibm)
September 8, 2026	RESCORED	RESCORED — CVE-2026-17255 (IBM i). CVSS 4.3 → 7.5 (NVD).

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
IBM	i	—	7.6	—

Weaknesses

CWE-787

References (1)

https://www.ibm.com/support/pages/node/7286093 [Patch, Vendor Advisory]

Authoritative record: CVE-2026-17255 at cve.org

Vendors: ibm

Weaknesses: CWE-787

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-17255 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Sunday, October 4, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.