CVE-2026-2447 in Firefox
Summary
by MITRE • 02/16/2026
Heap buffer overflow in libvpx. This vulnerability affects Firefox < 147.0.4, Firefox ESR < 140.7.1, Firefox ESR < 115.32.1, Thunderbird < 140.7.2, and Thunderbird < 147.0.2.
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Analysis
by VulDB Data Team • 03/10/2026
This heap buffer overflow vulnerability in libvpx represents a critical security flaw that impacts multiple Mozilla products including Firefox and Thunderbird browsers. The vulnerability stems from improper memory management within the libvpx library which is used for video encoding and decoding operations. When processing specially crafted video content, the library fails to properly validate buffer boundaries, leading to memory corruption that can be exploited by attackers to execute arbitrary code.
The technical nature of this vulnerability aligns with CWE-121, which describes heap-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations. This particular flaw occurs during the handling of video frames within the vp8 and vp9 video codecs that libvpx implements. The vulnerability manifests when the library processes malformed video data that triggers incorrect memory allocation or access patterns, potentially allowing an attacker to manipulate heap memory structures and gain control over the affected application's execution flow.
The operational impact of this vulnerability extends across multiple browser versions and represents a significant risk to end users who may encounter malicious video content in web pages, email attachments, or streaming media. Attackers can leverage this flaw by crafting specially designed video files or web content that, when processed by the vulnerable browser, triggers the buffer overflow condition. This exploitation can lead to complete system compromise, allowing attackers to execute malicious code with the privileges of the affected user. The vulnerability affects both regular Firefox releases and their extended support releases, indicating a widespread impact across different product lines and support cycles.
Mitigation strategies for this vulnerability include immediate patching of affected software versions, as recommended by Mozilla security advisories. Users should upgrade to Firefox version 147.0.4, Firefox ESR 140.7.1, Firefox ESR 115.32.1, Thunderbird version 140.7.2, or Thunderbird version 147.0.2 respectively. Organizations should implement network-based controls such as content filtering to prevent access to known malicious video content and deploy intrusion detection systems that can identify exploitation attempts. Additionally, browser hardening measures including sandboxing, memory protection mechanisms, and strict content security policies should be enabled to reduce the potential impact of successful exploitation attempts. The vulnerability also aligns with ATT&CK technique T1059.007 which covers command and scripting interpreter usage, as exploitation may involve execution of malicious code through compromised browser processes.