CVE-2023-6204
On some systems—depending on the graphics settings and drivers—it was possible to force an out-of-bounds read and leak memory data into the images created on the canvas element. This vulnerability affects Firefox < 120, Firefox ESR < 115.5.0, and Thunderbird < 115.5. Date published : 2023-11-21 https://www.debian.org/security/2023/dsa-5561