CVE-2025-11709 is a critical vulnerability in Firefox and Thunderbird where a compromised web process can cause out-of-bounds reads and writes in a more privileged process by manipulating WebGL textures. This flaw affects Firefox versions prior to 144 and Firefox ESR versions prior to 115.29 and 140.4, as well as Thunderbird versions prior to 144 and 140.4. The vulnerability allows potential arbitrary code execution due to memory corruption. Mozilla has released fixes in Firefox 144, Firefox ESR 115.29, and Firefox ESR 140.4, along with corresponding Thunderbird versions.