CVE-2025-10537: 
NixOS vulnerability analysis and mitigation

CVE-2025-10537 is a high-impact memory safety vulnerability affecting multiple Mozilla products including Firefox ESR 140.2, Thunderbird ESR 140.2, Firefox 142, and Thunderbird 142. The vulnerability was discovered by Andrew McCreight and the Mozilla Fuzzing Team and publicly disclosed on September 16, 2025 (Mozilla Advisory).

The vulnerability involves memory safety bugs that showed evidence of memory corruption. The issue is classified under CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) with a CVSS 3.1 base score of 8.8 (High), indicating a serious security risk. The attack vector is network-based (N), requiring low attack complexity (L) with no privileges required (N), but user interaction is required (R) (NVD).

These memory safety bugs could potentially be exploited to run arbitrary code on affected systems. The vulnerability impacts confidentiality, integrity, and availability with high severity ratings across all three aspects. For Thunderbird specifically, these flaws cannot be exploited through email as scripting is disabled when reading mail, but remain potential risks in browser or browser-like contexts (Mozilla Advisory).

Mozilla has released fixes in Firefox 143, Firefox ESR 140.3, Thunderbird 143, and Thunderbird ESR 140.3. Users are advised to update to these versions to mitigate the vulnerability (Mozilla Advisory).