# CVE-2026-18828: IBM AIX and PowerVM VIOS stack-based buffer overflow

Source: https://junglewise.ai/threats/cve-2026-18828-ibm-aix-and-powervm-vios-stack-based-buffer-overflow  
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-2026-18828 · Severity: medium · CVSS 5.4 · Published 2026-08-20

IBM AIX 7.2, 7.3 and PowerVM VIOS 4.1 contain a stack-based buffer overflow vulnerability that allows remote attackers to crash affected systems. This could cause service outages for organizations relying on these operating systems for mission-critical infrastructure and virtualization tasks.

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-2026-18828 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-18828 being exploited in the wild.

**How severe is CVE-2026-18828?** Medium severity, with a CVSS score of 5.4, 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-2026-18828?** 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-2026-18828 attacked?** It is attacked over the network, in an operating system.

**Am I affected by CVE-2026-18828?** 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

A stack-based buffer overflow exists in IBM AIX 7.2, 7.3 and PowerVM VIOS 4.1, allowing remote attackers to trigger a denial of service condition. The vulnerability is remotely exploitable without authentication or user interaction required. An attacker can send a crafted network request to overflow a stack buffer, causing the affected process to crash and resulting in availability impact. IBM has released security updates through Service Packs and Fix Packs to remediate this issue; affected systems should apply these patches promptly.

## Affected products

- IBM AIX 7.2, 7.3
- IBM PowerVM VIOS 4.1

## Timeline

- 2026-08-20: disclosed

## References

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

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