CVE-2025-10537: Memory safety bugs fixed in Firefox ESR 140.3, Thunderbird ESR 140.3, Firefox 143 and Thunderbird 143

Published Sep 16, 2025
·
Updated

Memory safety bugs present in Firefox ESR 140.2, Thunderbird ESR 140.2, Firefox 142 and Thunderbird 142. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 143, Firefox ESR 140.3, Thunderbird 143, and Thunderbird 140.3.

Other sources

Memory safety bugs present in Firefox ESR 140.2, Thunderbird ESR 140.2, Firefox 142 and Thunderbird 142. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 143 and Firefox ESR < 140.3.

— Red Hat

Memory safety bugs present in Firefox ESR 140.2, Thunderbird ESR 140.2, Firefox 142 and Thunderbird 142. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 143, Firefox ESR < 140.3, Thunderbird < 143, and Thunderbird < 140.3.

— OSV

Affected Software

25 affected componentsFixes available
Mozilla Firefox<143
Mozilla Firefox ESR<140.3
Mozilla Thunderbird<143
Mozilla Thunderbird ESR<140.3
Mozilla Thunderbird<143
143
Mozilla Firefox<140.3.0
Mozilla Firefox<143.0
Mozilla Thunderbird<140.3.0
Mozilla Thunderbird<143.0
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<143
143
Mozilla Firefox ESR<140.3
140.3
Mozilla Thunderbird<140.3
140.3
debian/firefox
160.0-1
debian/firefox-esr
140.12.0esr-1~deb12u1153.7.0esr-1~deb12u1140.15.0esr-1~deb13u1153.6.0esr-1~deb13u1153.5.1esr-1153.7.0esr-1
debian/thunderbird
1:140.12.0esr-1~deb12u11:153.6.0esr-1~deb12u21:140.12.0esr-1~deb13u11:153.6.0esr-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 143
  2. Upgrade

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

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

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

    Fixed in 140.3
  4. Upgrade

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

    Fixed in 160.0-1
  5. 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 153.6.0esr-1~deb13u1Fixed in 153.5.1esr-1Fixed in 153.7.0esr-1
  6. Upgrade

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

    Fixed in 1:140.12.0esr-1~deb12u1Fixed in 1:153.6.0esr-1~deb12u2Fixed in 1:140.12.0esr-1~deb13u1Fixed in 1:153.6.0esr-1~deb13u1Fixed in 1:153.5.0esr-1Fixed in 1:153.7.0esr-1
  7. Upgrade

    Upgrade Firefox to a version that resolves this vulnerability.

    Fixed in 143
  8. Upgrade

    Upgrade Firefox ESR to a version that resolves this vulnerability.

    Fixed in 140.3
  9. Upgrade

    Upgrade Thunderbird to a version that resolves this vulnerability.

    Fixed in 143
  10. Upgrade

    Upgrade Thunderbird ESR to a version that resolves this vulnerability.

    Fixed in 140.3

Event History

Sep 16, 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·12:26 PM
Data Sourced
via MITRE·12:26 PM
Description
Data Sourced
via Red Hat·01:02 PM
DescriptionSeverityAffected Software
Data Sourced
via OSV·01:15 PM
DescriptionSeverityAffected Software
Data Sourced
via NVD·01:15 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-2025-10537?

CVE-2025-10537 is considered a moderate severity vulnerability due to potential memory corruption and the risk of arbitrary code execution.

2

How do I fix CVE-2025-10537?

To fix CVE-2025-10537, update Firefox and Thunderbird to the latest versions, specifically beyond Firefox 143 and Thunderbird 143.

3

Which versions are affected by CVE-2025-10537?

CVE-2025-10537 affects Firefox versions up to 143, Firefox ESR up to 140.3, Thunderbird up to 143, and Thunderbird ESR up to 140.3.

4

What types of software are impacted by CVE-2025-10537?

CVE-2025-10537 impacts Mozilla Firefox, Firefox ESR, Mozilla Thunderbird, and Thunderbird ESR.

5

Is exploiting CVE-2025-10537 easy?

Exploiting CVE-2025-10537 may be possible with sufficient effort due to the memory safety bugs present, but it requires technical expertise.

Company

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Contact

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