An integer overflow flaw exists in Mozilla Firefox’s Widget: Win32 component. The CVE description states that the bug was addressed in Firefox 151 and Firefox ESR 140.11, indicating that earlier builds are vulnerable. The overflow could corrupt internal buffers or data structures if manipulated with malicious input, but the CVE does not assert an arbitrary code execution outcome.

Mozilla Firefox users running any version older than 151 or earlier ESR releases before 140.11 are affected. The vulnerability is limited to the Widget: Win32 component within these builds.

The CVSS score of 7.5 indicates a high severity, though no EPSS score is available and the issue is not listed in the CISA KEV catalog, implying that exploitation has not been observed in the wild. The attack vector is not explicitly stated; based on the description it is inferred to require access to the Widget: Win32 component, which suggests a local or privileged context rather than a purely remote attack.