CVE-2025-5268: Memory safety bugs fixed in Firefox 139, Thunderbird 139, Firefox ESR 128.11, and Thunderbird 128.11

Published May 27, 2025
·
Updated

Memory safety bugs present in Firefox 138, Thunderbird 138, Firefox ESR 128.10, and Thunderbird 128.10. 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 139, Firefox ESR 128.11, Thunderbird 139, and Thunderbird 128.11.

Other sources

Memory safety bugs present in Firefox 138, Thunderbird 138, Firefox ESR 128.10, and Thunderbird 128.10. 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 < 139 and Firefox ESR < 128.11.

— Red Hat

Affected Software

25 affected componentsFixes available
Mozilla Firefox<139
Mozilla Thunderbird<139
Mozilla Firefox ESR<128.11
Mozilla Thunderbird<128.11
Mozilla Thunderbird<139
139
Mozilla Firefox<128.11.0
Mozilla Firefox<139.0
Mozilla Thunderbird<128.11.0
Mozilla Thunderbird>=129.0<139.0
ubuntu/mozjs52*
ubuntu/mozjs38*
ubuntu/mozjs68*
ubuntu/mozjs52*
ubuntu/mozjs102*
ubuntu/mozjs78*
ubuntu/mozjs91*
ubuntu/thunderbird<1:128.12.0+build1-0ubuntu0.22.04.1
1:128.12.0+build1-0ubuntu0.22.04.1
ubuntu/mozjs102*
ubuntu/mozjs115*
Mozilla Firefox ESR<128.11
128.11
Mozilla Firefox<139
139
Mozilla Thunderbird<128.11
128.11
debian/firefox
159.0.1-1
debian/firefox-esr
140.12.0esr-1~deb12u1153.6.0esr-1~deb12u2140.15.0esr-1~deb13u1153.6.0esr-1~deb13u1153.5.1esr-1153.6.0esr-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-11:153.6.0esr-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 139
  2. Upgrade

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

    Fixed in 1:128.12.0+build1-0ubuntu0.22.04.1
  3. Upgrade

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

    Fixed in 128.11
  4. Upgrade

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

    Fixed in 159.0.1-1
  5. Upgrade

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

    Fixed in 140.12.0esr-1~deb12u1Fixed in 153.6.0esr-1~deb12u2Fixed in 140.15.0esr-1~deb13u1Fixed in 153.6.0esr-1~deb13u1Fixed in 153.5.1esr-1Fixed in 153.6.0esr-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 1:153.6.0esr-1
  7. Upgrade

    Upgrade Firefox to a version that resolves this vulnerability.

    Fixed in 139
  8. Upgrade

    Upgrade Firefox ESR to a version that resolves this vulnerability.

    Fixed in 128.11
  9. Upgrade

    Upgrade Thunderbird to a version that resolves this vulnerability.

    Fixed in 139
  10. Upgrade

    Upgrade Thunderbird ESR to a version that resolves this vulnerability.

    Fixed in 128.11

Event History

May 27, 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·12:29 PM
Data Sourced
via MITRE·12:29 PM
Description
Data Sourced
via Red Hat·01:01 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-2025-5268?

CVE-2025-5268 is considered a high severity vulnerability due to the potential for memory corruption that could allow arbitrary code execution.

2

How do I fix CVE-2025-5268?

To fix CVE-2025-5268, update your Mozilla Firefox or Thunderbird to version 139 or Mozilla Firefox ESR to version 128.11.

3

What versions are affected by CVE-2025-5268?

CVE-2025-5268 affects Mozilla Firefox versions up to 138, Thunderbird versions up to 138, and Firefox ESR versions up to 128.10.

4

What types of software are impacted by CVE-2025-5268?

CVE-2025-5268 impacts Mozilla Firefox, Mozilla Thunderbird, and Mozilla Firefox ESR.

5

Are there any known exploits for CVE-2025-5268?

While there is no confirmation of active exploits, the nature of CVE-2025-5268 indicates that it could potentially be exploited with sufficient technical effort.

Company

Resources

Contact

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