An incorrect boundary condition in the SVG component can cause malformed SVG files to be processed incorrectly, leading to program crashes or hangs. The flaw involves integer overflows and improper input validation, which may overflow buffers during rendering and abort execution. The high CVSS score reflects the potential for an attacker to deliver such a crafted file and force a denial of service on the affected system.

Mozilla Firefox and Mozilla Thunderbird prior to version 158.0.1 are affected. These browsers contain the SVG rendering engine that contains the flawed integer validation logic.

The CVSS score of 9.8 classifies the issue as critical, while the EPSS score of less than 1% suggests a low likelihood of exploitation. The vulnerability is not listed in the CISA KEV catalog, indicating no publicly known exploits. Likely attack vectors involve delivering a crafted SVG via a web page, email attachment, or local file to trigger the crash. Given the high severity, the vendor recommends immediate patching, even though the exploitation probability is low.