Use-after-free vulnerability in the CanonicalizeXPCOMParticipant function in Mozilla Firefox before 48.0 and Firefox ESR 45.x before 45.3 allows remote attackers to execute arbitrary code via a script that closes its own Service Worker within a nested sync event loop.

Use-after-free vulnerability in the WebRTC socket thread in Mozilla Firefox before 48.0 and Firefox ESR 45.x before 45.3 allows remote attackers to execute arbitrary code by leveraging incorrect free operations on DTLS objects during the shutdown of a WebRTC session.

Use-after-free vulnerability in the nsXULPopupManager::KeyDown function in Mozilla Firefox before 48.0 and Firefox ESR 45.x before 45.3 allows attackers to execute arbitrary code or cause a denial of service (heap memory corruption and application crash) by leveraging keyboard access to use the Alt key during selection of top-level menu items.

Stack-based buffer underflow in the mozilla::gfx::BasePoint4d function in Mozilla Firefox before 48.0 and Firefox ESR 45.x before 45.3 allows remote attackers to execute arbitrary code via crafted two-dimensional graphics data that is mishandled during clipping-region calculations.

Mozilla Firefox before 48.0 and Firefox ESR 45.x before 45.3 on Linux make cairo _cairo_surface_get_extents calls that do not properly interact with libav header allocation in FFmpeg 0.10, which allows remote attackers to cause a denial of service (application crash) via a crafted video.

Heap-based buffer overflow in the nsBidi::BracketData::AddOpening function in Mozilla Firefox before 48.0 and Firefox ESR 45.x before 45.3 allows remote attackers to execute arbitrary code via directional content in an SVG document.

Heap-based buffer overflow in the ClearKey Content Decryption Module (CDM) in the Encrypted Media Extensions (EME) API in Mozilla Firefox before 48.0 and Firefox ESR 45.x before 45.3 might allow remote attackers to execute arbitrary code by providing a malformed video and leveraging a Gecko Media Plugin (GMP) sandbox bypass.

Multiple unspecified vulnerabilities in the browser engine in Mozilla Firefox before 48.0 and Firefox ESR 45.x before 45.3 allow remote attackers to cause a denial of service (memory corruption and application crash) or possibly execute arbitrary code via vectors related to Http2Session::Shutdown and SpdySession31::Shutdown, and other vectors.

Mozilla Firefox before 48.0 and Firefox ESR 45.x before 45.3 preserve the network connection used for favicon resource retrieval after the associated browser window is closed, which makes it easier for remote web servers to track users by observing network traffic from multiple IP addresses.