CVE-2025-0238 is a use-after-free vulnerability in Firefox related to handling line breaks in text, which can be triggered by a controlled failed memory allocation. This memory safety issue could cause a crash that might be exploited. The vulnerability affects Firefox versions prior to 134 and Firefox ESR versions prior to 128.6. Mozilla has released official patches in Firefox 134 and Firefox ESR 128.6 to address this issue. The CVSS 3.1 base score is 5.3 (medium), reflecting a network attack vector with low complexity and no privileges or user interaction required, impacting confidentiality but not integrity or availability.

The vulnerability can cause a use-after-free condition leading to a potentially exploitable crash, which may allow an attacker to compromise confidentiality. There is no indication of impact on integrity or availability. No known exploits have been reported in the wild. The issue is mitigated by applying the official patches provided by Mozilla.

An official fix is available and has been released in Firefox 134 and Firefox ESR 128.6. Users and administrators should update to these versions or later to remediate this vulnerability. No additional mitigation actions are required beyond applying the vendor-provided patches.