CVE-2026-17136Network attack vector

Unauthenticated code execution via controlled format string

Published Aug 20, 2026 · Updated Aug 25, 2026

Externally controlled format strings in IBM AIX 7.2 and 7.3 and PowerVM VIOS 4.1 allow remote attackers to execute arbitrary code. IBM has not identified the affected component or input, but the published weakness means an external string is used as a formatting argument. No authentication or user interaction is required, and successful exploitation runs attacker-chosen code on the target.

CVSS severity9.8
Critical
EPSS probability0.60%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Externally controlled format strings in IBM AIX 7.2 and 7.3 and PowerVM VIOS 4.1 allow remote attackers to execute arbitrary code. IBM has not identified the affected component or input, but the published weakness means an external string is used as a formatting argument. No authentication or user interaction is required, and successful exploitation runs attacker-chosen code on the target.

The record

CVE
CVE-2026-17136
Published
Aug 20, 2026
Updated
Aug 25, 2026
Vendor
IBM
Product
AIX
Classifications
CWE-134
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 20, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 25, 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?

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

Published CVSS scores

9.8IBMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/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.

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-134Use of Externally-Controlled Format String

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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