CVE-2026-18846

Analyzed Analyzed - Analysis Complete

Buffer Overflow in IBM i Leading to Denial of Service

Publication date: 2026-08-13

Last updated on: 2026-08-17

Assigner: IBM Corporation

Description

IBM i 7.6, 7.5, 7.4, and 7.3 s vulnerable to a buffer overflow from improperly validating client data. By sending malformed requests to one of the host servers, a remote attacker could leverage this vulnerability to cause a denial-of-server (DoS) for that server.

CVSS Scores

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Meta Information

Published

2026-08-13

Last Modified

2026-08-17

Generated

2026-09-03

AI Q&A

2026-08-14

EPSS Evaluated

2026-09-02

NVD

CVE-2026-18846

EUVD

EUVD-2026-58239

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-787	The product writes data past the end, or before the beginning, of the intended buffer.

Attack-Flow Graph

Executive Summary

This vulnerability is a buffer overflow issue in IBM i versions 7.6, 7.5, 7.4, and 7.3. It occurs because the system fails to properly validate client data sent to host servers. Attackers can exploit this by sending malformed requests, causing a denial-of-service (DoS) condition on the affected server.

Detection Guidance

Detecting this vulnerability requires monitoring for malformed requests targeting IBM i host servers. Check network traffic for unusual patterns or payloads directed at IBM i services. Use packet inspection tools like tcpdump or Wireshark to capture and analyze requests. Monitor server logs for crashes or errors indicating buffer overflow attempts.

Impact Analysis

If exploited, this vulnerability could disrupt the availability of IBM i servers by causing them to crash or become unresponsive. This may lead to downtime for services relying on these servers, potentially affecting business operations.

Compliance Impact

This vulnerability could potentially impact compliance with GDPR and HIPAA by enabling denial-of-service attacks that disrupt server availability. GDPR requires maintaining data availability, while HIPAA mandates access to protected health information systems. A DoS condition may violate these requirements if it affects critical data processing or access.

Mitigation Strategies

Apply IBM i PTFs or updates to address the buffer overflow vulnerability. Monitor network traffic for malformed requests targeting host servers. Restrict access to vulnerable servers if possible.

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