CVE-2026-18839

Received Received - Intake

Integer Underflow in Popt Library Causes Application Crash

Publication date: 2026-08-05

Last updated on: 2026-08-05

Assigner: Red Hat, Inc.

Description

An integer underflow was found in the popt library when formatting help text for option tables that exceed the terminal width. A local user who can cause an application to print help under those conditions may cause that application to crash or fail to display help, resulting in a denial of service of the affected application.

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-08-05

Last Modified

2026-08-05

Generated

2026-08-06

AI Q&A

2026-08-06

EPSS Evaluated

N/A

NVD

CVE-2026-18839

Affected Vendors & Products

Currently, no data is known.

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-191	The product subtracts one value from another, such that the result is less than the minimum allowable integer value, which produces a value that is not equal to the correct result.

Attack-Flow Graph

Executive Summary

This vulnerability is an integer underflow in the popt library. It occurs when formatting help text for option tables that exceed the terminal width. A local user could exploit this to cause an application to crash or fail to display help, leading to a denial of service.

Detection Guidance

This vulnerability involves an integer underflow in the popt library when formatting help text for option tables exceeding terminal width. Detection requires checking if any applications using popt are installed and if they can be triggered to print help text with wide option tables. No specific commands are provided in the context.

Impact Analysis

If you are a local user who can trigger help text display in an affected application, this vulnerability could cause the application to crash or stop showing help content. This may disrupt your ability to use the application normally.

Mitigation Strategies

Update the popt library to the latest version to address the integer underflow issue. Monitor application crashes or help text display failures when option tables exceed terminal width. Apply patches from your distribution if available.

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