CVE-2026-16827Network attack vector

Denial of service via uninitialized stack pointer

Published Aug 19, 2026 · Updated Aug 19, 2026

Denial of service in IBM AIX 7.2 and 7.3 and IBM PowerVM Virtual I/O Server 4.1 allows remote attackers to crash the host. IBM has disclosed only that affected code uses an uninitialized stack pointer while handling attacker-reachable input; the specific subsystem or function is not public. IBM's CVSS record scopes the outcome to availability, so triage depends on whether untrusted remote parties can reach the vulnerable service path on AIX or VIOS systems.

CVSS severity5.9
Medium
EPSS probability0.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in IBM AIX 7.2 and 7.3 and IBM PowerVM Virtual I/O Server 4.1 allows remote attackers to crash the host. IBM has disclosed only that affected code uses an uninitialized stack pointer while handling attacker-reachable input; the specific subsystem or function is not public. IBM's CVSS record scopes the outcome to availability, so triage depends on whether untrusted remote parties can reach the vulnerable service path on AIX or VIOS systems.

The record

CVE
CVE-2026-16827
Published
Aug 19, 2026
Updated
Aug 19, 2026
Vendor
OpenBMC Project
Product
AIX
Classifications
CWE-908, T1499
Attack vector
network
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 vectornetwork
Required privilegesunauthenticated

What is affected?

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

Published CVSS scores

5.9IBMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

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

Weakness, pattern, technique

CWE-908Use of Uninitialized Resource
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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