CVE-2026-2793: Memory safety bugs fixed in Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird ESR 140.8, Firefox 148 and Thunderbird 148

Published Feb 24, 2026
·
Updated

Memory safety bugs present in Firefox ESR 115.32, Firefox ESR 140.7, Thunderbird ESR 140.7, Firefox 147 and Thunderbird 147. 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.

Affected Software

10 affected componentsFixes available
Mozilla Firefox<148
148
Mozilla Firefox ESR<140.8
140.8
Mozilla Firefox ESR<115.33
115.33
Mozilla Thunderbird<148
148
Mozilla Thunderbird<140.8
140.8
Mozilla Firefox<115.33.0
Mozilla Firefox<148.0
Mozilla Firefox>=128.0<140.8.0
Mozilla Thunderbird<140.8.0
Mozilla Thunderbird<148.0

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 148
  2. Upgrade

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

    Fixed in 140.8
  3. Upgrade

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

    Fixed in 115.33
  4. Upgrade

    Upgrade Firefox to a version that resolves this vulnerability.

    Fixed in 148
  5. Upgrade

    Upgrade Firefox ESR to a version that resolves this vulnerability.

    Fixed in 115.33
  6. Upgrade

    Upgrade Firefox ESR to a version that resolves this vulnerability.

    Fixed in 140.8
  7. Upgrade

    Upgrade Thunderbird to a version that resolves this vulnerability.

    Fixed in 148
  8. Upgrade

    Upgrade Thunderbird ESR to a version that resolves this vulnerability.

    Fixed in 140.8

Event History

Feb 24, 2026
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·01:33 PM
Data Sourced
via MITRE·01:33 PM
Description
Data Sourced
via Red Hat·02:02 PM
DescriptionSeverityAffected Software
Data Sourced
via NVD·02:16 PM
DescriptionSeverityWeaknessAffected Software
Jan 4, 58137
Event
via FIRST·12:42 PM

Parent advisories

This vulnerability appears in the following advisories.

Peer vulnerabilities

Found alongside the following vulnerabilities.

Free Weekly Intel

Don't miss critical vulnerabilities

Join thousands of security professionals who receive our weekly digest of trending CVEs, zero-days, and exploited vulnerabilities.

No spam. Unsubscribe anytime.

Frequently Asked Questions

1

What is the severity of CVE-2026-2793?

CVE-2026-2793 has been classified as a moderate severity vulnerability due to its memory safety bugs.

2

How do I fix CVE-2026-2793?

To fix CVE-2026-2793, update to Firefox ESR 115.33, Firefox ESR 140.8, Firefox 148, or Thunderbird 148.

3

Which versions of Firefox are affected by CVE-2026-2793?

CVE-2026-2793 affects Firefox versions prior to 148 and Firefox ESR versions prior to 140.8.

4

Is Thunderbird affected by CVE-2026-2793?

Yes, Thunderbird versions prior to 148 and Thunderbird ESR versions prior to 140.8 are affected by CVE-2026-2793.

5

What type of vulnerabilities are involved in CVE-2026-2793?

CVE-2026-2793 involves memory safety bugs that could lead to memory corruption.

Company

Resources

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203