Mozilla Firefox ESR Security Update (mfsa_2026-03) - Windows

Mozilla Firefox ESR is prone to multiple vulnerabilities. SPDX-FileCopyrightText: 2026 Greenbone AG Some text descriptions might be excerpted from a referenced sources, and are Copyright C by the respective right holders. SPDX-License-Identifier: GPL-2.0-only CPE = "cpe:/a:mozilla:firefoxesr";...

CVE-2026-0886

Incorrect boundary conditions in the Graphics component. This vulnerability affects Firefox 147, Firefox ESR 115.32, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7...

CVE-2026-0884

Use-after-free in the JavaScript Engine component. This vulnerability was fixed in Firefox 147, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7...

CVE-2026-0880

Sandbox escape due to integer overflow in the Graphics component. This vulnerability was fixed in Firefox 147, Firefox ESR 115.32, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7...

CVE-2026-0887

Clickjacking issue, information disclosure in the PDF Viewer component. This vulnerability was fixed in Firefox 147, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7...

CVE-2026-0879

Sandbox escape due to incorrect boundary conditions in the Graphics component. This vulnerability was fixed in Firefox 147, Firefox ESR 115.32, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7...

Astra Linux – Vulnerability in Firefox, Thunderbird

JIT compilation errors in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 146, Firefox ESR 115.31, Firefox ESR 140.6, Thunderbird 146, and Thunderbird 140.6...

Astra Linux – Vulnerability in Firefox, Thunderbird

Use-after-free in the WebRTC: Signaling component. This vulnerability was fixed in Firefox 146, Firefox ESR 140.6, Thunderbird 146, and Thunderbird 140.6...

CVE-2026-0891 Memory safety bugs fixed in Firefox ESR 140.7, Thunderbird ESR 140.7, Firefox 147 and Thunderbird 147

Memory safety bugs present in Firefox ESR 140.6, Thunderbird ESR 140.6, Firefox 146 and Thunderbird 146. 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. This vulnerability was fixed in...

CVE-2026-0891

CVE-2026-0891 corresponds to memory-safety bugs in Mozilla products: Firefox ESR 140.6, Thunderbird ESR 140.6, Firefox 146 and Thunderbird 146. The issue is described as memory corruption in certain bugs that could, with sufficient effort, be exploited to execute arbitrary code. Affected products...

CVE-2026-0887

Clickjacking issue, information disclosure in the PDF Viewer component. This vulnerability was fixed in Firefox 147, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7...

CVE-2026-0887

Clickjacking issue, information disclosure in the PDF Viewer component. This vulnerability was fixed in Firefox 147, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7...

CVE-2026-0886

Incorrect boundary conditions in the Graphics component. This vulnerability was fixed in Firefox 147, Firefox ESR 115.32, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7...

CVE-2026-0883

CVE-2026-0883 corresponds to information disclosure in the Networking component affecting Mozilla Firefox versions below 147 (and Firefox ESR below 140.7) and Mozilla Thunderbird versions below 147 (and Thunderbird ESR below 140.7). The linked advisories and Debian advisories list this CVE among ...

CVE-2026-0884

Use-after-free in the JavaScript Engine component. This vulnerability was fixed in Firefox 147, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7...

CVE-2026-0882

Use-after-free in the IPC component. This vulnerability affects Firefox 147, Firefox ESR 115.32, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7...

CVE-2026-0882 Use-after-free in the IPC component

Use-after-free in the IPC component. This vulnerability was fixed in Firefox 147, Firefox ESR 115.32, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7...

CVE-2026-0880

CVE-2026-0880 is a sandbox-escape vulnerability: sandbox escape due to an integer overflow in the Graphics component. Affected products include Firefox (<147), Firefox ESR (<115.32 and <140.7), Thunderbird (<147 and

CVE-2026-0879

Sandbox escape due to incorrect boundary conditions in the Graphics component. This vulnerability was fixed in Firefox 147, Firefox ESR 115.32, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7...

CVE-2026-0878 Sandbox escape due to incorrect boundary conditions in the Graphics: CanvasWebGL component

Sandbox escape due to incorrect boundary conditions in the Graphics: CanvasWebGL component. This vulnerability was fixed in Firefox 147, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7...