# CVE-2026-18835: IBM AIX and PowerVM VIOS command injection vulnerability

Source: https://junglewise.ai/threats/cve-2026-18835-ibm-aix-and-powervm-vios-command-injection-vulnerability  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-20. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-18835 · Severity: critical · CVSS 9.9 · Published 2026-08-20

IBM AIX 7.2 and 7.3, and IBM PowerVM VIOS 4.1 contain a command injection flaw in the NIM (Network Installation Manager) component that allows authenticated remote attackers to execute arbitrary operating system commands. An attacker with valid credentials could exploit this to gain unauthorized system access, modify files, or launch further attacks within the affected infrastructure.

Technologies: [IBM Aix](https://junglewise.ai/threats/technologies/aix), [IBM PowerVM VIOS](https://junglewise.ai/threats/technologies/powervm-vios). Vendors: [IBM](https://junglewise.ai/threats/vendors/ibm).

## Quick answers

**Is CVE-2026-18835 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-18835 being exploited in the wild.

**How severe is CVE-2026-18835?** Critical severity, with a CVSS score of 9.9, published 20 August 2026.

**Which products and versions are affected?** IBM Aix 7.2, 7.3; IBM PowerVM VIOS 4.1.

**Is there a fix for CVE-2026-18835?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-18835 attacked?** It is attacked over the network, in an operating system.

**Am I affected by CVE-2026-18835?** Check whether you run IBM Aix or IBM PowerVM VIOS at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability is an improper neutralization of special elements used in an OS command (CWE-78 command injection) within IBM AIX 7.2, 7.3, and PowerVM VIOS 4.1. The flaw exists in the Network Installation Manager (NIM) component, which fails to properly sanitize user-supplied input before passing it to OS command execution routines. An authenticated remote attacker can exploit this by crafting malicious input containing shell metacharacters to break out of the intended command context and execute arbitrary commands with the privileges of the NIM process. The vulnerability requires valid authentication credentials but operates over the network. Security patches delivered via Service Packs (SPs) and Fix Packs (FPs) are available from IBM.

## Affected products

- IBM AIX 7.2, 7.3
- IBM PowerVM VIOS 4.1

## Timeline

- 2026-08-20: disclosed: Vulnerability disclosed by IBM

## References

- [https://www.ibm.com/support/pages/node/7283858](https://www.ibm.com/support/pages/node/7283858)

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