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-2026-16821

CVE-2026-16821HIGH

IBM AIX — Vulnerabilities in IBM AIX and PowerVM VIOS

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   L   L   L   N  U  H  H  H    7.8   .0010    0.7     —

AFFECTED
  Product       Versions  Fixed
  AIX           7.2 –     —
  PowerVM VIOS  4.1 –     —

TIMELINE
  Jul 24  Reserved by ibm
  Aug 28  Published (CNA: ibm)
  Sep 2   RESCORED — CVE-2026-16821 (IBM AIX). CVSS 7 → 7.8 (NVD).

CWE-134 · CNA: ibm · CVSS v3.1 · 1 reference · NVD status: Analyzed

Description

IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a local attacker to gain elevated privileges due to a format string vulnerability.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
July 24, 2026	Reserved	Reserved by ibm
August 28, 2026	Published	Published (CNA: ibm)
September 2, 2026	RESCORED	RESCORED — CVE-2026-16821 (IBM AIX). CVSS 7 → 7.8 (NVD).

Affected

Affected products and packages — 2 rows
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
IBM	AIX	—	7.2	—
IBM	PowerVM VIOS	—	4.1	—

Weaknesses

CWE-134

References (1)

https://www.ibm.com/support/pages/node/7283858 [Patch, Vendor Advisory]

Authoritative record: CVE-2026-16821 at cve.org

Vendors: ibm

Weaknesses: CWE-134

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-16821 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.