CVE-2025-1009

Name of the Vulnerable Software and Affected Versions Firefox versions prior to 135 Firefox ESR versions prior to 115.20 Firefox ESR versions prior to 128.7 Thunderbird versions prior to 128.7 Thunderbird versions prior to 135

Description An attacker could have caused a use-after-free via crafted XSLT data, leading to a potentially exploitable crash. The issue arises from the failure to reset the mCompileResult in the txMozillaXSLTProcessor::ImportStylesheet, resulting in a stale error state that persists, causing subsequent transformations to use freed memory and leading to a use-after-free condition.

Recommendations For Firefox versions prior to 135, update to version 135 or later. For Firefox ESR versions prior to 115.20, update to version 115.20 or later. For Firefox ESR versions prior to 128.7, update to version 128.7 or later. For Thunderbird versions prior to 128.7, update to version 128.7 or later. For Thunderbird versions prior to 135, update to version 135 or later. As a temporary workaround, consider disabling the use of XSLT data in affected applications until a patch is available.