CVE-2026-18828

Service interruption via undisclosed stack buffer overflow

Published Aug 20, 2026 · Updated Aug 20, 2026

Stack-based buffer overflow in IBM AIX 7.2 and 7.3 and PowerVM VIOS 4.1 allows remote attackers to interrupt service over an adjacent network. IBM has not disclosed the affected component, the input that reaches it, or the unchecked stack-buffer operation. The attack requires neither authentication nor user interaction and causes service interruption without reported integrity impact.

CVSS severity5.4
Medium
EPSS probability0.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-based buffer overflow in IBM AIX 7.2 and 7.3 and PowerVM VIOS 4.1 allows remote attackers to interrupt service over an adjacent network. IBM has not disclosed the affected component, the input that reaches it, or the unchecked stack-buffer operation. The attack requires neither authentication nor user interaction and causes service interruption without reported integrity impact.

The record

CVE
CVE-2026-18828
Published
Aug 20, 2026
Updated
Aug 20, 2026
Vendor
IBM
Product
AIX
Classifications
CWE-787, T1499.004
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 20, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 20, 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 vectoradjacent
Required privilegesunauthenticated

What is affected?

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

Published CVSS scores

5.4IBMCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L

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)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1499.004Application or System Exploitation

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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