Mozilla Firefox is an open-source web browser, designed for standards compliance, performance, and portability. This update upgrades Firefox to version 115.6.0 ESR. Security Fix(es): * Mozilla: Heap-buffer-overflow affecting WebGL DrawElementsInstanced method with Mesa VM driver (CVE-2023-6856) * Mozilla: Memory safety bugs fixed in Firefox 121, Firefox ESR 115.6, and Thunderbird 115.6 (CVE-2023-6864) * Mozilla: Potential exposure of uninitialized data in EncryptingOutputStream (CVE-2023-6865) * Mozilla: Symlinks may resolve to smaller than expected buffers (CVE-2023-6857) * Mozilla: Heap buffer overflow in nsTextFragment (CVE-2023-6858) * Mozilla: Use-after-free in PR_GetIdentitiesLayer (CVE-2023-6859) * Mozilla: Potential sandbox escape due to VideoBridge lack of texture validation (CVE-2023-6860) * Mozilla: Heap buffer overflow affected nsWindow::PickerOpen(void) in headless mode (CVE-2023-6861) * Mozilla: Use-after-free in nsDNSService (CVE-2023-6862) * Mozilla: Clickjacking permission prompts using the popup transition (CVE-2023-6867) * Mozilla: Undefined behavior in ShutdownObserver() (CVE-2023-6863) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.