---
id: CVE-2026-113399
title: Incorrect boundary conditions in the SVG component
summary: >-
  Incorrect boundary conditions in the SVG component. This vulnerability was
  fixed in Firefox 158.0.1 and Thunderbird 158.0.1.
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cvssSource: adp
vendor: Mozilla
product: Firefox
affected:
  - Firefox
  - Thunderbird
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: total
  timestamp: '2026-10-29T17:43:33.677361Z'
published: '2026-10-20'
updated: '2026-10-29'
sourceUpdated: '2026-10-29T17:44:03.368Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-113399'
references:
  - url: 'https://bugzilla.mozilla.org/show_bug.cgi?id=2079938'
  - url: 'https://www.mozilla.org/security/advisories/mfsa2026-111/'
  - url: 'https://www.mozilla.org/security/advisories/mfsa2026-114/'
tags:
  - cve.org
epss: 0.00489
epssPercentile: 0.42071
ingestedAt: '2026-10-20T14:08:00.583Z'
---

## Overview

Incorrect boundary conditions in the SVG component. This vulnerability was fixed in Firefox 158.0.1 and Thunderbird 158.0.1.

## Affected

- `Firefox`
- `Thunderbird`

## Remediation

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