---
id: CVE-2026-18839
title: >-
  An integer underflow was found in the popt library when formatting help text
  for option tables that exceed the terminal width
summary: >-
  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 c…
severity: low
cvss: 2.2
cvssVector: 'CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:L'
cwe:
  - CWE-191
vendor: rpm-software-management
product: popt
affected:
  - popt >= 1.13 < *
  - popt-main (all versions)
  - popt (all versions)
  - popt
  - popt (all versions)
  - popt (all versions)
  - popt (all versions)
  - openshift/ose-rhel-coreos-8 (all versions)
  - openshift/ose-rhel-coreos-9 (all versions)
published: '2026-08-05'
updated: '2026-10-08'
sourceUpdated: '2026-10-08T15:17:52.650'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-18839'
references:
  - url: 'https://access.redhat.com/errata/RHSA-2026:77932'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/security/cve/CVE-2026-18839'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2511010'
    label: secalert@redhat.com
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-18839.json
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-18839'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-18839'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-08-06T13:33:56.244752Z'
epss: 0.00126
epssPercentile: 0.023
ingestedAt: '2026-10-08T15:49:37.974Z'
patched:
  - hardened_images
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **RHSA-2026:77932** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-10-07 · [advisory](https://access.redhat.com/errata/RHSA-2026:77932)
- **Red Hat VEX** · Low · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, … · updated 2026-10-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-18839.json)