CVE-2025-4920: Critical severity firefox vulnerability

Published May 17, 2025
·
Updated

An attacker was able to perform an out-of-bounds read or write on a JavaScript Promise object.

Other sources

Rejected reason: Duplicate of CVE-2025-4918

NVD

Affected Software

4 affected componentsFixes available
Mozilla Firefox<138.0.4
Mozilla Firefox ESR<128.10.1
Mozilla Firefox<138.0.4
138.0.4
Mozilla Firefox ESR<128.10.1
128.10.1

Event History

May 17, 2025
CVE Published
via Mozilla·12:00 AM
CVE Published
via MITRE·09:07 PM
Rejected
via MITRE·09:07 PM
Data Sourced
via NVD·10:15 PM
Description
May 18, 2025
Rejected
via MITRE·07:21 PM

Parent advisories

This vulnerability appears in the following advisories.

Peer vulnerabilities

Found alongside the following vulnerabilities.

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Frequently Asked Questions

1

What is the severity of CVE-2025-4920?

CVE-2025-4920 is classified as a high-severity vulnerability that can lead to out-of-bounds read or write on JavaScript Promise objects.

2

How do I fix CVE-2025-4920?

To fix CVE-2025-4920, update Firefox to version 138.0.4 or Firefox ESR to version 128.10.1.

3

What versions of Firefox are affected by CVE-2025-4920?

CVE-2025-4920 affects all Firefox versions prior to 138.0.4 and Firefox ESR versions prior to 128.10.1.

4

What type of attack does CVE-2025-4920 facilitate?

CVE-2025-4920 facilitates potential out-of-bounds read or write attacks through a vulnerable JavaScript Promise object.

5

Is CVE-2025-4920 present in the latest Firefox release?

No, CVE-2025-4920 is not present in the latest Firefox release starting from version 138.0.4.

Contact

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