Mozilla Foundation

Mozilla Releases Firefox 158.0.1 Security Update Fixing High-Severity Vulnerabilities and Compromised Certificates

Mozilla Foundation has published Firefox 158.0.1 on October 20, 2026, delivering fixes for four CVEs rated at high overall severity. Two vulnerabilities received a High rating, including a boundary condition flaw in the SVG component tracked as CVE-2026-113399 and a certificate blocklist issue identified as CVE-2026-113470. The update also refreshes the OneCRL list to block an intermediate certificate from eMudhra that was compromised earlier in the month. Mozilla delivered the updated blocklist via RemoteSettings on October 17 and embedded the changes directly into the browser release. This approach ensures compromised certificates remain blocked even when RemoteSettings is disabled or network access is unavailable. One Moderate and one Low severity issue complete the set of addressed flaws.

Mozilla Releases Firefox 157 with 76 Security Fixes, Shifts to Individual CVE Reporting

Mozilla Foundation has released Firefox 157, addressing 76 vulnerabilities rated at various severity levels. The update also includes patches for the extended support releases Firefox ESR 153.4, ESR 140.17, and ESR 115.42. A key change in this release involves Mozilla's new approach to publishing security advisories, moving from grouping multiple memory safety issues under single CVEs to reporting them individually. Among the high-severity issues fixed are sandbox escape flaws, privilege escalation bugs, use-after-free errors, uninitialized memory problems, and JIT compiler mistakes affecting components such as DOM, Graphics, WebGPU, WebAssembly, and Networking. The ESR versions received 62, 43, and 31 fixes respectively, with 34 rated high in the latest branch. All listed CVEs range from CVE-2026-100756 through CVE-2026-100831.

Mozilla Releases Firefox 153 Fixing 63 Vulnerabilities Including Critical ESR Issues

Mozilla Foundation released Firefox 153 on July 21, 2026, addressing a total of 63 vulnerabilities tracked under CVE identifiers. The update also covers the Firefox ESR branch, where several flaws already had public exploit code available, earning a Critical severity rating. Among the High-severity issues resolved are same-origin policy bypasses in navigation handling such as CVE-2026-16349 and multiple memory-safety problems. The release further patches Use-After-Free vulnerabilities including CVE-2026-16362 and several sandbox escape flaws designated CVE-2026-16351, CVE-2026-16352, CVE-2026-16356, and CVE-2026-16367. Additional fixes cover boundary condition errors, integer overflows, miscompilation issues, privilege escalation vectors, and information disclosure problems. In total the advisory lists 20 High, 35 Moderate, and 8 Low severity vulnerabilities that have been mitigated.