CVE-2025-4918
Out-of-bounds access when resolving Promise objects
CVSS Score
9.8
EPSS Score
0.0%
EPSS Percentile
0th
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.
| Vendor | mozilla |
| Product | firefox |
| Ecosystems | |
| Industries | Technology |
| Published | May 17, 2025 |
| Last Updated | Apr 13, 2026 |
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Affected Versions
Mozilla / Firefox
All versions affected Mozilla / Thunderbird
All versions affected References
bugzilla.mozilla.org: https://bugzilla.mozilla.org/show_bug.cgi?id=1966612 mozilla.org: https://www.mozilla.org/security/advisories/mfsa2025-36/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2025-37/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2025-38/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2025-40/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2025-41/ vicarius.io: https://www.vicarius.io/vsociety/posts/cve-2025-4918-detect-firefox-out-of-bounds-write vicarius.io: https://www.vicarius.io/vsociety/posts/cve-2025-4918-mitigate-firefox-out-of-bounds-write lists.debian.org: https://lists.debian.org/debian-lts-announce/2025/05/msg00046.html lists.debian.org: https://lists.debian.org/debian-lts-announce/2025/05/msg00024.html
Credits
Edouard Bochin and Tao Yan from Palo Alto Networks working with Trend Micro's Zero Day Initiative