CVE-2025-8027: JavaScript engine only wrote partial return value to stack

Published Jul 22, 2025
·
Updated

On 64-bit platforms IonMonkey-JIT only wrote 32 bits of the 64-bit return value space on the stack. Baseline-JIT, however, read the entire 64 bits.

Affected Software

14 affected componentsFixes available
Mozilla Firefox ESR<115.26
115.26
Mozilla Firefox<141
141
Mozilla Firefox ESR<128.13
128.13
Mozilla Firefox ESR<140.1
140.1
Mozilla Thunderbird<128.13
128.13
Mozilla Thunderbird<141
141
Mozilla Thunderbird<140.1
140.1
Mozilla Firefox<115.26.0
Mozilla Firefox<141.0
Mozilla Firefox>=128.0<128.13.0
Mozilla Firefox>=140.0<140.1.0
Mozilla Thunderbird<128.13.0
Mozilla Thunderbird<141.0
Mozilla Thunderbird>=140.0<140.1.0

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 115.26
  2. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 128.13
  3. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 140.1
  4. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 141
  5. Upgrade

    Upgrade Mozilla Firefox to a version that resolves this vulnerability.

    Fixed in 141
  6. Upgrade

    Upgrade Mozilla Firefox ESR to a version that resolves this vulnerability.

    Fixed in 115.26
  7. Upgrade

    Upgrade Mozilla Firefox ESR to a version that resolves this vulnerability.

    Fixed in 128.13
  8. Upgrade

    Upgrade Mozilla Firefox ESR to a version that resolves this vulnerability.

    Fixed in 140.1
  9. Upgrade

    Upgrade Mozilla Thunderbird to a version that resolves this vulnerability.

    Fixed in 141
  10. Upgrade

    Upgrade Mozilla Thunderbird to a version that resolves this vulnerability.

    Fixed in 128.13
  11. Upgrade

    Upgrade Mozilla Thunderbird to a version that resolves this vulnerability.

    Fixed in 140.1

Event History

Jul 22, 2025
CVE Published
via Mozilla·12:00 AM
Data Sourced
via Mozilla·12:00 AM
DescriptionSeverityAffected Software
Updated
via Mozilla·12:00 AM
Affected Software
CVE Published
via MITRE·08:49 PM
Data Sourced
via MITRE·08:49 PM
Description
Data Sourced
via Red Hat·09:01 PM
DescriptionSeverityAffected Software
Data Sourced
via NVD·09:15 PM
DescriptionSeverityWeaknessAffected Software

Parent advisories

This vulnerability appears in the following advisories.

Frequently Asked Questions

1

What is the severity of CVE-2025-8027?

CVE-2025-8027 has a high severity rating due to potential exploitation leading to execution of arbitrary code.

2

How do I fix CVE-2025-8027?

To fix CVE-2025-8027, update your Mozilla Firefox to the latest version beyond the affected versions, which include Firefox ESR 115.26 and others.

3

What products are affected by CVE-2025-8027?

CVE-2025-8027 affects Mozilla Firefox and Firefox ESR versions up to 115.26, 141, 128.13, and 140.1.

4

What is the nature of CVE-2025-8027 vulnerability?

CVE-2025-8027 is a vulnerability related to IonMonkey-JIT and Baseline-JIT handling of 64-bit return values on 64-bit platforms.

5

Is there a workaround for CVE-2025-8027?

There is no known workaround for CVE-2025-8027, so updating to a fixed version is the recommended mitigation.

Contact

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