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. This vulnerability was fixed in Firefox 141, Firefox ESR 115.26, Firefox ESR 128.13, Firefox ESR 140.1, Thunderbird 141, Thunderbird 128.13, and Thunderbird 140.1.

Other sources

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. This vulnerability affects Firefox < 141, Firefox ESR < 115.26, Firefox ESR < 128.13, Firefox ESR < 140.1, Thunderbird < 141, Thunderbird < 128.13, and Thunderbird < 140.1.

— Red Hat

Affected Software

27 affected componentsFixes available
Mozilla Firefox ESR<115.26
115.26
Mozilla Firefox ESR<140.1
140.1
Mozilla Thunderbird<140.1
140.1
Mozilla Thunderbird<141
141
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
ubuntu/mozjs52*
ubuntu/mozjs38*
ubuntu/mozjs68*
ubuntu/mozjs52*
ubuntu/mozjs102*
ubuntu/mozjs78*
ubuntu/mozjs91*
ubuntu/thunderbird<1:140.7.1+build1-0ubuntu0.22.04.1
1:140.7.1+build1-0ubuntu0.22.04.1
ubuntu/mozjs102*
ubuntu/mozjs115*
Mozilla Firefox<141
141
Mozilla Firefox ESR<128.13
128.13
Mozilla Thunderbird<128.13
128.13
debian/firefox
160.0-1
debian/firefox-esr
140.12.0esr-1~deb12u1153.7.0esr-1~deb12u1140.15.0esr-1~deb13u1153.7.0esr-1~deb13u1153.5.1esr-1153.7.0esr-1
debian/thunderbird
1:140.12.0esr-1~deb12u11:153.7.0esr-1~deb12u11:140.12.0esr-1~deb13u11:153.7.0esr-1~deb13u11:153.5.0esr-11:153.7.0esr-1

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 140.1
  3. Upgrade

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

    Fixed in 141
  4. Upgrade

    Upgrade ubuntu/thunderbird to a version that resolves this vulnerability.

    Fixed in 1:140.7.1+build1-0ubuntu0.22.04.1
  5. Upgrade

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

    Fixed in 128.13
  6. Upgrade

    Upgrade debian/firefox to a version that resolves this vulnerability.

    Fixed in 160.0-1
  7. Upgrade

    Upgrade debian/firefox-esr to a version that resolves this vulnerability.

    Fixed in 140.12.0esr-1~deb12u1Fixed in 153.7.0esr-1~deb12u1Fixed in 140.15.0esr-1~deb13u1Fixed in 153.7.0esr-1~deb13u1Fixed in 153.5.1esr-1Fixed in 153.7.0esr-1
  8. Upgrade

    Upgrade debian/thunderbird to a version that resolves this vulnerability.

    Fixed in 1:140.12.0esr-1~deb12u1Fixed in 1:153.7.0esr-1~deb12u1Fixed in 1:140.12.0esr-1~deb13u1Fixed in 1:153.7.0esr-1~deb13u1Fixed in 1:153.5.0esr-1Fixed in 1:153.7.0esr-1
  9. Upgrade

    Upgrade Firefox to a version that resolves this vulnerability.

    Fixed in 141
  10. Upgrade

    Upgrade Firefox ESR to a version that resolves this vulnerability.

    Fixed in 115.26
  11. Upgrade

    Upgrade Firefox ESR to a version that resolves this vulnerability.

    Fixed in 128.13
  12. Upgrade

    Upgrade Firefox ESR to a version that resolves this vulnerability.

    Fixed in 140.1
  13. Upgrade

    Upgrade Thunderbird to a version that resolves this vulnerability.

    Fixed in 141
  14. Upgrade

    Upgrade Thunderbird to a version that resolves this vulnerability.

    Fixed in 128.13
  15. Upgrade

    Upgrade 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
Data Sourced
via Ubuntu·12:00 AM
RemedyDescriptionSeverityAffected 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 OSV·09:15 PM
DescriptionSeverityAffected Software
Data Sourced
via NVD·09:15 PM
DescriptionSeverityWeaknessAffected Software

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-2025-8027?

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.

Company

Resources

Contact

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