# CVE-2026-18343: IBM i improper privilege management in BOOTP table

Source: https://junglewise.ai/threats/cve-2026-18343-ibm-i-7-3-7-4-7-5-and-7-6-could-allow-a-local-attacker-to-modify  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-13. Updated: 2026-10-16  
License: CC BY 4.0 with a link back

CVE-2026-18343 · Severity: medium · CVSS 4.4 · Published 2026-10-13

IBM i is an operating system used for running mission-critical business applications on Power Systems servers. A local attacker with limited privileges can improperly modify the BOOTP table, which controls network boot configuration, potentially disrupting network operations or redirecting boot traffic. This requires the attacker to already have local access to the system.

Technologies: [IBM I](https://junglewise.ai/threats/technologies/i). Vendors: [IBM](https://junglewise.ai/threats/vendors/ibm).

## Quick answers

**Is CVE-2026-18343 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-18343 being exploited in the wild.

**How severe is CVE-2026-18343?** Medium severity, with a CVSS score of 4.4, published 13 October 2026.

**Which products and versions are affected?** IBM I 7.3, 7.4, 7.5, 7.6.

**Is there a fix for CVE-2026-18343?** Yes: fixed in IBM i 7.6 (PTF SJ11460), 7.5 (PTF SJ11461), 7.4 (PTF SJ11462), 7.3 (PTF SJ11463). Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-18343 attacked?** It is attacked with local access, in an operating system.

**Am I affected by CVE-2026-18343?** Check whether you run IBM I 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.

## How to fix

- Fixed in IBM i 7.6 (PTF SJ11460), 7.5 (PTF SJ11461), 7.4 (PTF SJ11462), 7.3 (PTF SJ11463)

## Technical details

An improper privilege management vulnerability (CWE-269) in IBM i versions 7.3–7.6 allows a local user with basic privileges to modify the BOOTP (Bootstrap Protocol) table without proper authorization checks. The attack requires local access and no user interaction. An attacker could redirect or manipulate network boot operations, affecting system availability and potentially enabling network-layer attacks.

## Affected products

- IBM i 7.3, 7.4, 7.5, 7.6

## Timeline

- 2026-09-30: disclosed
- 2026-10-13: advisory

## References

- [https://www.ibm.com/support/pages/node/7290194](https://www.ibm.com/support/pages/node/7290194)

## Related threats

- [IBM i Navigator authentication bypass via improper access control](https://junglewise.ai/threats/cve-2026-93744-ibm-i-7-3-7-4-7-5-and-7-6-could-allow-an-unathenticated-remote)
- [IBM i ChrootDirectory security restriction bypass in OpenSSH](https://junglewise.ai/threats/cve-2026-17491-ibm-i-7-3-7-4-7-5-and-7-6-is-could-allow-a-remote-authenticated)
- [IBM i improper authentication bypass in SST/DST](https://junglewise.ai/threats/cve-2026-17488-ibm-i-7-3-7-4-7-5-and-7-6-could-allow-a-remote-authenticated)
- [IBM i file handle access control vulnerability in NFS](https://junglewise.ai/threats/cve-2026-17073-ibm-i-7-3-7-4-7-5-and-7-6-could-allow-a-local-attacker-to-obtain)
- [IBM i NFS version restriction bypass](https://junglewise.ai/threats/cve-2026-17068-ibm-i-7-3-7-4-7-5-and-7-6-could-allow-a-local-attacker-to-bypass)