Parsing a JavaScript module as JSON could, under some circumstances, cause cross-compartment access, which may result in a use-after-free. This vulnerability affects Firefox < 134, Firefox ESR < 128.6, Thunderbird < 134, and Thunderbird < 128.6.
{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_name": "firefox",
            "binary_version": "134.0+build1-0ubuntu0.20.04.1"
        },
        {
            "binary_name": "firefox-dev",
            "binary_version": "134.0+build1-0ubuntu0.20.04.1"
        },
        {
            "binary_name": "firefox-geckodriver",
            "binary_version": "134.0+build1-0ubuntu0.20.04.1"
        },
        {
            "binary_name": "firefox-mozsymbols",
            "binary_version": "134.0+build1-0ubuntu0.20.04.1"
        }
    ]
}