Platform
firefox
Component
firefox
Fixed in
150
CVE-2026-6748 describes a memory corruption vulnerability discovered in Mozilla Firefox. This flaw resides within the Audio/Video: Web Codecs component and could potentially allow for remote code execution. The vulnerability impacts Firefox versions 140.10 and earlier, as well as related Thunderbird versions. A fix is available in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.
Successful exploitation of CVE-2026-6748 could allow an attacker to trigger a denial-of-service (DoS) by crashing the Firefox browser. More critically, the uninitialized memory condition could be leveraged to execute arbitrary code within the context of the user's browser session. This could lead to data theft, malware installation, or complete compromise of the affected system. The Web Codecs component handles audio and video processing, making it a potentially attractive target for attackers seeking to exploit vulnerabilities in media playback.
CVE-2026-6748 was published on April 21, 2026. As of this writing, there are no publicly available exploits or active campaigns targeting this vulnerability. The EPSS score is pending evaluation. Monitor security advisories and threat intelligence feeds for any updates regarding exploitation attempts.
Exploit Status
EPSS
0.06% (20% percentile)
The primary mitigation for CVE-2026-6748 is to upgrade to a patched version of Firefox, Firefox ESR, Thunderbird, or Thunderbird. Upgrade to Firefox 150, Firefox ESR 140.10, Thunderbird 150, or Thunderbird 140.10 as soon as possible. If immediate patching is not feasible, consider implementing stricter content security policies (CSP) to limit the execution of untrusted code within the browser. While a WAF cannot directly mitigate this vulnerability, it can help detect and block malicious requests targeting the Web Codecs component. After upgrading, confirm the fix by attempting to reproduce the vulnerability using known exploit techniques (if available) or by verifying the browser version.
Update to the latest version of Firefox (150 or later) to mitigate this vulnerability. The update patches the uninitialized memory issue in the Web Codecs component, preventing potential attacks. See the release notes for more details.
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CVE-2026-6748 is a memory corruption vulnerability in Mozilla Firefox affecting versions 140.10 and earlier. It resides in the Web Codecs component and could lead to crashes or code execution.
You are affected if you are using Mozilla Firefox or Thunderbird versions 140.10 or earlier. Check your browser version using the command 'firefox --version' or 'thunderbird --version'.
Upgrade to Firefox 150, Firefox ESR 140.10, Thunderbird 150, or Thunderbird 140.10. This resolves the memory corruption issue in the Web Codecs component.
As of now, there are no publicly known exploits or active campaigns targeting CVE-2026-6748. However, it's crucial to apply the patch promptly to prevent potential future exploitation.
Refer to the official Mozilla security advisory for detailed information and updates regarding CVE-2026-6748: [https://www.mozilla.org/en-US/security/advisories/](https://www.mozilla.org/en-US/security/advisories/)
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