Boundary Condition Flaw in Mozilla Firefox and ESR Versions
CVE-2026-4714

7.5HIGH

Key Information:

Vendor

Mozilla
Status
Firefox
Firefox Esr
Thunderbird
Vendor
CVE Published:
24 March 2026

What is CVE-2026-4714?

This vulnerability arises from incorrect boundary conditions within the Audio/Video component of Mozilla Firefox, affecting versions prior to 149 and Firefox ESR versions below 140.9. Exploitation of this weakness could lead to unexpected behavior, potentially compromising user data or system integrity. Users are encouraged to update their browsers to the latest versions to mitigate any risks associated with this flaw.

Affected Version(s)

Firefox < 149

Firefox ESR < 140.9

Thunderbird < 149

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2018126
https://www.mozilla.org/security/advisories/mfsa2026-20/
https://www.mozilla.org/security/advisories/mfsa2026-22/

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Sajeeb Lohani
.