CVE-2026-16819

Data corruption and denial of service via TOCTOU

Published Aug 19, 2026 · Updated Aug 19, 2026

TOCTOU race conditions in IBM AIX 7.2 and 7.3 and PowerVM VIOS 4.1 allow local users to corrupt data and crash the system. IBM has not disclosed the affected function or resource, only that state can change between its security check and subsequent use. Local access without prior privileges is required; successful exploitation can compromise data integrity and interrupt the logical partition.

CVSS severity7.7
High
EPSS probability0.09%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

TOCTOU race conditions in IBM AIX 7.2 and 7.3 and PowerVM VIOS 4.1 allow local users to corrupt data and crash the system. IBM has not disclosed the affected function or resource, only that state can change between its security check and subsequent use. Local access without prior privileges is required; successful exploitation can compromise data integrity and interrupt the logical partition.

The record

CVE
CVE-2026-16819
Published
Aug 19, 2026
Updated
Aug 19, 2026
Vendor
IBM
Product
AIX
Classifications
CWE-367
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 19, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=7.2
  2. Affected versionversion=7.3

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

IBM · AIXversion=7.2; version=7.3
IBM · PowerVM Virtual I/O Serverversion=4.1

Published CVSS scores

7.7IBMCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-367Time-of-check Time-of-use (TOCTOU) Race Condition

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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