---
id: CVE-2026-100817
title: 'Other issue in the JavaScript: WebAssembly component'
summary: >-
  Other issue in the JavaScript: WebAssembly component. This vulnerability was
  fixed in Thunderbird 157 and Firefox 157.
severity: medium
cvss: 5.4
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N'
vendor: mozilla
product: firefox
affected:
  - firefox < 157.0.0
  - thunderbird < 157.0
patched:
  - firefox 157.0.0
  - thunderbird 157.0
published: '2026-09-29'
updated: '2026-10-06'
sourceUpdated: '2026-10-06T14:35:41.210'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-100817'
references:
  - url: 'https://bugzilla.mozilla.org/show_bug.cgi?id=2068670'
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2026-101/'
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2026-97/'
    label: security@mozilla.org
tags:
  - nvd
  - cve.org
epss: 0.00197
epssPercentile: 0.09354
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-10-01T15:36:50.438550Z'
ingestedAt: '2026-09-29T13:34:31.675Z'
---

## Overview

Other issue in the JavaScript: WebAssembly component. This vulnerability was fixed in Thunderbird 157 and Firefox 157.

## Affected

- `firefox < 157.0.0`
- `thunderbird < 157.0`

## Remediation

Upgrade past the affected range:

- `firefox 157.0.0`
- `thunderbird 157.0`