JavaScript Engine Vulnerability in Firefox by Mozilla
CVE-2026-109716

8.1HIGH

Key Information:

Vendor

Mozilla
Status
Firefox
Thunderbird
Vendor
CVE Published:
13 October 2026

What is CVE-2026-109716?

This vulnerability originates from incorrect boundary conditions in the JavaScript Engine component of Firefox. It can lead to unexpected behavior and potential security risks. Mozilla has addressed this issue in the updates for Firefox 158, Firefox ESR 115.43, and Firefox ESR 153.5, emphasizing the importance of keeping software up to date to safeguard against potential exploitation.

Affected Version(s)

Firefox 115.43

Firefox 153.5

Firefox 158

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2073269
https://www.mozilla.org/security/advisories/mfsa2026-106/
https://www.mozilla.org/security/advisories/mfsa2026-107/

CVSS V3.1

Score:
8.1
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
Required
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Amy Burnett of OpenAI
.