CVE-2026-81858

Analyzed Analyzed - Analysis Complete

IBM i File Server Out-of-Bounds Read Vulnerability

Publication date: 2026-10-13

Last updated on: 2026-10-14

Assigner: IBM Corporation

Description

IBM i 7.3, 7.4, 7.5, and 7.6 could allow a remote authenticated attacker to cause a denial of service and obtain information due to an out-of-bounds read in the File Server.

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-10-13

Last Modified

2026-10-14

Generated

2026-10-19

AI Q&A

2026-10-13

EPSS Evaluated

2026-10-18

NVD

CVE-2026-81858

EUVD

EUVD-2026-98178

Affected Vendors & Products

Vendor	Product	Version / Range
ibm	i	From 7.3 (inc) to 7.6 (inc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-125	The product reads data past the end, or before the beginning, of the intended buffer.

Attack-Flow Graph

Executive Summary

IBM i 7.3, 7.4, 7.5, and 7.6 are vulnerable to a denial of service (DoS) attack due to an out-of-bounds read flaw in the File Server component. A remote authenticated attacker could exploit this to cause a DoS condition and potentially access sensitive information.

Detection Guidance

Detection involves checking for IBM i File Server vulnerabilities. Monitor for unusual network traffic or crashes. Use IBM i commands like DSPPTF to verify applied PTFs and WRKPTFGRP to check for missing fixes. Review system logs for errors related to the File Server component.

Impact Analysis

This vulnerability could allow attackers to disrupt services by causing a DoS condition. It may also enable unauthorized access to sensitive data, impacting system availability and confidentiality.

Compliance Impact

This vulnerability could potentially impact compliance with GDPR and HIPAA due to the risk of unauthorized information disclosure and service disruption. The out-of-bounds read flaw may allow remote attackers to access sensitive data, which could violate GDPR's data protection requirements or HIPAA's confidentiality rules if exploited.

Mitigation Strategies

Apply the provided IBM PTF fixes for your IBM i version (7.3, 7.4, 7.5, or 7.6) immediately. If running an unsupported version, upgrade to a supported release. Disable unnecessary File Server services if not required. Monitor IBM support pages for updates.

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