Critical severity · published May 17, 2025
CVE-2025-4918
An attacker was able to perform an out-of-bounds read or write on a JavaScript `Promise` object
9.8
CVSS
9.5%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)9.5% · higher than 95% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FI
Firefox · Mozilla
before 115.23.1; before 138.0.4; 116.0 before 128.10.1 · source: NVD
TH
Thunderbird · Mozilla
before 128.10.2; 138.0 before 138.0.2 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-4918
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-4918
Permissions Required
https://bugzilla.mozilla.org/show_bug.cgi?id=1966612
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-36/
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-37/
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-38/
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-40/
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-41/
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