---
id: CVE-2026-117915
title: 'Incorrect boundary conditions in the Layout: Block and Inline component'
summary: >-
  Incorrect boundary conditions in the Layout: Block and Inline component. This
  vulnerability was fixed in Firefox 159, Firefox ESR 115.44, Firefox ESR 153.6,
  Thunderbird 159, and Thunderbird 153.6.
severity: none
vendor: Mozilla
product: Firefox
affected:
  - Firefox
  - Thunderbird
published: '2026-10-27'
updated: '2026-10-27'
sourceUpdated: '2026-10-27T18:28:55.577Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-117915'
references:
  - url: 'https://bugzilla.mozilla.org/show_bug.cgi?id=2079255'
  - url: 'https://www.mozilla.org/security/advisories/mfsa2026-118/'
  - url: 'https://www.mozilla.org/security/advisories/mfsa2026-119/'
  - url: 'https://www.mozilla.org/security/advisories/mfsa2026-120/'
  - url: 'https://www.mozilla.org/security/advisories/mfsa2026-121/'
  - url: 'https://www.mozilla.org/security/advisories/mfsa2026-122/'
tags:
  - cve.org
ingestedAt: '2026-10-27T16:11:59.385Z'
---

## Overview

Incorrect boundary conditions in the Layout: Block and Inline component. This vulnerability was fixed in Firefox 159, Firefox ESR 115.44, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.

## Affected

- `Firefox`
- `Thunderbird`

## Remediation

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