CVE-2025-4918: Out-of-bounds access when resolving Promise objects
An attacker was able to perform an out-of-bounds read or write on a JavaScript Promise object. This vulnerability affects Firefox ESR < 115.23.1.
Other sources
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.
— MITRE
An attacker was able to perform an out-of-bounds read or write on a JavaScript Promise object.
— Mozilla
Affected Software
Event History
Parent advisories
This vulnerability appears in the following advisories.
Peer vulnerabilities
Found alongside the following vulnerabilities.
Frequently Asked Questions
What is the severity of CVE-2025-4918?
CVE-2025-4918 is classified as a high severity vulnerability due to its potential to allow attackers to read or write out-of-bounds memory.
How do I fix CVE-2025-4918?
To mitigate CVE-2025-4918, update your Mozilla Firefox ESR to version 115.23.2 or later.
What types of attacks can exploit CVE-2025-4918?
CVE-2025-4918 can be exploited through specifically crafted JavaScript that targets Promise objects, leading to out-of-bounds memory access.
Who is affected by CVE-2025-4918?
CVE-2025-4918 affects users of Mozilla Firefox ESR versions up to and including 115.23.1.
Is CVE-2025-4918 being actively exploited in the wild?
There are currently no confirmed reports of CVE-2025-4918 being actively exploited in the wild.