Mozilla Foundation Security Advisory 2026-25

Security Vulnerabilities fixed in Firefox 149.0.2

Announced
April 7, 2026
Impact
high
Products
Firefox
Fixed in
  • Firefox 149.0.2

#CVE-2026-5732: Incorrect boundary conditions, integer overflow in the Graphics: Text component

Reporter
Sajeeb Lohani
Impact
high
References

#CVE-2026-5733: Incorrect boundary conditions in the Graphics: WebGPU component

Reporter
Inseo An
Impact
high
References

#CVE-2026-5731: Memory safety bugs fixed in Firefox ESR 115.34.1, Firefox ESR 140.9.1, Thunderbird ESR 140.9.1, Firefox 149.0.2 and Thunderbird 149.0.2

Reporter
Brian Grinstead, Christian Holler, Tom Schuster and the Mozilla Fuzzing Team
Impact
high
Description

Memory safety bugs present in Firefox ESR 115.34.0, Firefox ESR 140.9.0, Thunderbird ESR 140.9.0, Firefox 149.0.1 and Thunderbird 149.0.1. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code.

References

#CVE-2026-5734: Memory safety bugs fixed in Firefox ESR 140.9.1, Thunderbird ESR 140.9.1, Firefox 149.0.2 and Thunderbird 149.0.2

Reporter
Brian Grinstead, Christian Holler, Tom Schuster and the Mozilla Fuzzing Team
Impact
high
Description

Memory safety bugs present in Firefox ESR 140.9.0, Thunderbird ESR 140.9.0, Firefox 149.0.1 and Thunderbird 149.0.1. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code.

References

#CVE-2026-5735: Memory safety bugs fixed in Firefox 149.0.2 and Thunderbird 149.0.2

Reporter
Brian Grinstead, Christian Holler and the Mozilla Fuzzing Team
Impact
high
Description

Memory safety bugs present in Firefox 149.0.1 and Thunderbird 149.0.1. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code.

References