Incorrect Boundary Conditions in Firefox Layout Component
CVE-2026-109753

8.1HIGH

Key Information:

Vendor

Mozilla
Status
Firefox
Thunderbird
Vendor
CVE Published:
13 October 2026

What is CVE-2026-109753?

A vulnerability exists in the layout component of Firefox, where incorrect boundary conditions may lead to unintended behaviors. This flaw can potentially be exploited by attackers to manipulate application responses or disrupt service stability. The issue has been addressed with updates in Firefox versions 158, Firefox ESR 115.43, and Firefox ESR 153.5, ensuring enhanced security and reliability.

Affected Version(s)

Firefox 115.43

Firefox 153.5

Firefox 158

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2068441
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

Mozilla
.