# CVE-2026-18318: IBM i brute-force attack on authentication in DST/SST

Source: https://junglewise.ai/threats/cve-2026-18318-ibm-i-7-3-7-4-7-5-and-7-6-could-allow-a-remote-attacker-to  
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-2026-18318 · Severity: medium · CVSS 5.3 · Published 2026-10-13

IBM i is a business-critical operating system used to run enterprise applications and data management systems. This vulnerability allows a remote attacker to perform brute-force attacks against user credentials with no restrictions, potentially compromising access to sensitive business systems and data. The flaw exists in the Dedicated Service Tools (DST) and System Service Tools (SST) components that manage system administration and maintenance.

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

## Quick answers

**Is CVE-2026-18318 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-18318 being exploited in the wild.

**How severe is CVE-2026-18318?** Medium severity, with a CVSS score of 5.3, 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-2026-18318?** Yes: fixed in IBM i 7.6 with PTF MJ11636 or MJ11441; IBM i 7.5 with PTF MJ11635 or MJ11439; IBM i 7.4 with PTF MJ11634 or MJ11438; IBM i 7.3 with PTF MJ11633 or MJ11448. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-18318 attacked?** It is attacked over the network, in an operating system.

**Am I affected by CVE-2026-18318?** Check whether you run IBM I or 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 with PTF MJ11636 or MJ11441; IBM i 7.5 with PTF MJ11635 or MJ11439; IBM i 7.4 with PTF MJ11634 or MJ11438; IBM i 7.3 with PTF MJ11633 or MJ11448

## Technical details

The vulnerability stems from improper restriction of excessive authentication attempts (CWE-307), allowing remote attackers to conduct unrestricted brute-force attacks on credentials. No authentication or user interaction is required; the attack is purely network-based and unauthenticated. Successful exploitation allows an attacker to obtain valid user credentials and gain unauthorized access to the system.

## Affected products

- IBM IBM i 7.3, 7.4, 7.5, 7.6

## Timeline

- 2026-09-29: disclosed
- 2026-10-13: advisory

## References

- [https://www.ibm.com/support/pages/node/7290096](https://www.ibm.com/support/pages/node/7290096)

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