CVE-2025-4918

critical

Description

An attacker was able to perform an out-of-bounds read or write on a JavaScript `Promise` object. This vulnerability was fixed in Firefox 138.0.4, Firefox ESR 128.10.1, Firefox ESR 115.23.1, Thunderbird 128.10.2, and Thunderbird 138.0.2.

References

References
More

https://www.bleepingcomputer.com/news/security/mozilla-fixes-firefox-zero-days-exploited-at-hacking-contest/

https://thehackernews.com/2025/05/firefox-patches-2-zero-days-exploited.html

https://securityaffairs.com/178064/security/mozilla-fixed-zero-days-demonstrated-at-pwn2own-berlin-2025.html

https://github.com/AndrewAltimit/exploits

https://github.com/korden-c/CVE-2025-4918

https://github.com/hendrewna/CVE-2025-4918

https://github.com/Totunm/CVE-2025-4918

https://www.mozilla.org/security/advisories/mfsa2025-41/

https://www.mozilla.org/security/advisories/mfsa2025-40/

https://www.mozilla.org/security/advisories/mfsa2025-38/

https://www.mozilla.org/security/advisories/mfsa2025-37/

https://www.mozilla.org/security/advisories/mfsa2025-36/

https://lists.debian.org/debian-lts-announce/2025/05/msg00046.html

https://lists.debian.org/debian-lts-announce/2025/05/msg00024.html

https://bugzilla.mozilla.org/show_bug.cgi?id=1966612

Details

Source: Mitre, NVD

Published: 2025-05-17

Updated: 2026-04-13

Risk Information

CVSS v2

Base Score: 10

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

Severity: Critical

CVSS v3

Base Score: 9.8

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H