Mozilla Foundation Security Advisory 2026-14

Security Vulnerabilities fixed in Firefox ESR 115.33

Announced
February 24, 2026
Impact
high
Products
Firefox ESR
Fixed in
  • Firefox ESR 115.33

#CVE-2026-2757: Incorrect boundary conditions in the WebRTC: Audio/Video component

Reporter
Igor Morgenstern
Impact
high
References

#CVE-2026-2758: Use-after-free in the JavaScript: GC component

Reporter
Gary Kwong
Impact
high
References

#CVE-2026-2759: Incorrect boundary conditions in the Graphics: ImageLib component

Reporter
stevej
Impact
high
References

#CVE-2026-2760: Sandbox escape due to incorrect boundary conditions in the Graphics: WebRender component

Reporter
Oskar L
Impact
high
References

#CVE-2026-2761: Sandbox escape in the Graphics: WebRender component

Reporter
Oskar L
Impact
high
References

#CVE-2026-2763: Use-after-free in the JavaScript Engine component

Reporter
Information to follow
Impact
high
References

#CVE-2026-2764: JIT miscompilation, use-after-free in the JavaScript Engine: JIT component

Reporter
Information to follow
Impact
high
References

#CVE-2026-2769: Use-after-free in the Storage: IndexedDB component

Reporter
Information to follow
Impact
high
References

#CVE-2026-2770: Use-after-free in the DOM: Bindings (WebIDL) component

Reporter
Information to follow
Impact
high
References

#CVE-2026-2771: Undefined behavior in the DOM: Core & HTML component

Reporter
Information to follow
Impact
high
References

#CVE-2026-2772: Use-after-free in the Audio/Video: Playback component

Reporter
Information to follow
Impact
high
References

#CVE-2026-2773: Incorrect boundary conditions in the Web Audio component

Reporter
Information to follow
Impact
high
References

#CVE-2026-2774: Integer overflow in the Audio/Video component

Reporter
Information to follow
Impact
high
References

#CVE-2026-2775: Mitigation bypass in the DOM: HTML Parser component

Reporter
Information to follow
Impact
high
References

#CVE-2026-2776: Sandbox escape due to incorrect boundary conditions in the Telemetry component in External Software

Reporter
Sajeeb Lohani
Impact
high
References

#CVE-2026-2777: Privilege escalation in the Messaging System component

Reporter
Richard Belisle
Impact
high
References

#CVE-2026-2778: Sandbox escape due to incorrect boundary conditions in the DOM: Core & HTML component

Reporter
Sajeeb Lohani
Impact
high
References

#CVE-2026-2787: Use-after-free in the DOM: Window and Location component

Reporter
Information to follow
Impact
moderate
References

#CVE-2026-2788: Incorrect boundary conditions in the Audio/Video: GMP component

Reporter
Information to follow
Impact
moderate
References

#CVE-2026-2789: Use-after-free in the Graphics: ImageLib component

Reporter
Information to follow
Impact
moderate
References

#CVE-2026-2793: Memory safety bugs fixed in Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird ESR 140.8, Firefox 148 and Thunderbird 148

Reporter
Andrew McCreight, Christian Holler
Impact
high
Description

Memory safety bugs present in Firefox ESR 115.32, Firefox ESR 140.7, Thunderbird ESR 140.7, Firefox 147 and Thunderbird 147. 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