CVE-2025-4919
HIGHCVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Lifecycle Timeline
3Description
An attacker was able to perform an out-of-bounds read or write on a JavaScript object by confusing array index sizes. This vulnerability affects Firefox < 138.0.4, Firefox ESR < 128.10.1, Firefox ESR < 115.23.1, Thunderbird < 128.10.2, and Thunderbird < 138.0.2.
Analysis
An attacker was able to perform an out-of-bounds read or write on a JavaScript object by confusing array index sizes. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Technical Context
This vulnerability is classified as Out-of-bounds Read (CWE-125), which allows attackers to read data from memory outside the intended buffer boundaries. An attacker was able to perform an out-of-bounds read or write on a JavaScript object by confusing array index sizes. This vulnerability affects Firefox < 138.0.4, Firefox ESR < 128.10.1, Firefox ESR < 115.23.1, Thunderbird < 128.10.2, and Thunderbird < 138.0.2. Affected products include: Mozilla Firefox, Mozilla Thunderbird.
Affected Products
Mozilla Firefox, Mozilla Thunderbird.
Remediation
No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Validate array indices and buffer lengths. Use memory-safe languages. Enable AddressSanitizer during testing.
Priority Score
Vendor Status
Share
External POC / Exploit Code
Leaving vuln.today