CVE-2025-4918: Out-of-bounds access when resolving Promise objects

Published May 17, 2025
·
Updated

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

10 affected componentsFixes available
Mozilla Firefox ESR<115.23.1
115.23.1
Mozilla Firefox<138.0.4
138.0.4
Mozilla Firefox ESR<128.10.1
128.10.1
Mozilla Thunderbird<138.0.2
138.0.2
Mozilla Thunderbird<128.10.2
128.10.2
Mozilla Firefox<115.23.1
Mozilla Firefox<138.0.4
Mozilla Firefox>=116.0<128.10.1
Mozilla Thunderbird<128.10.2
Mozilla Thunderbird>=138.0<138.0.2

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade Firefox ESR to a version that resolves this vulnerability.

    Fixed in 115.23.1
  2. Upgrade

    Upgrade Firefox to a version that resolves this vulnerability.

    Fixed in 138.0.4
  3. Upgrade

    Upgrade Firefox ESR to a version that resolves this vulnerability.

    Fixed in 128.10.1
  4. Upgrade

    Upgrade Thunderbird to a version that resolves this vulnerability.

    Fixed in 138.0.2
  5. Upgrade

    Upgrade Thunderbird to a version that resolves this vulnerability.

    Fixed in 128.10.2

Event History

May 17, 2025
CVE Published
via Mozilla·12:00 AM
CVE Published
via MITRE·09:07 PM
Data Sourced
via MITRE·09:07 PM
Description
Data Sourced
via Red Hat·10:01 PM
DescriptionSeverityAffected Software
Data Sourced
via NVD·10:15 PM
DescriptionSeverityWeaknessAffected Software
May 19, 2025
News Published
via BleepingComputer·02:03 PM
News Published
via BleepingComputer·02:10 PM
News Published
via BleepingComputer·02:12 PM
May 23, 2025
Known Exploited
02:05 PM

Parent advisories

This vulnerability appears in the following advisories.

Peer vulnerabilities

Found alongside the following vulnerabilities.

Frequently Asked Questions

1

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.

2

How do I fix CVE-2025-4918?

To mitigate CVE-2025-4918, update your Mozilla Firefox ESR to version 115.23.2 or later.

3

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.

4

Who is affected by CVE-2025-4918?

CVE-2025-4918 affects users of Mozilla Firefox ESR versions up to and including 115.23.1.

5

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.

Company

Resources

Contact

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