CVE-2026-100760: Sandbox escape in the Security: Process Sandboxing component

Published Sep 29, 2026
·
Updated

Sandbox escape in the Security: Process Sandboxing component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 153.4, and Firefox 157.

Affected Software

11 affected componentsFixes available
Mozilla Thunderbird<157
157
Mozilla Firefox<153.4.0
Mozilla Firefox>=154.0.0<157.0.0
Mozilla Thunderbird<153.4.0
Mozilla Thunderbird>=154.0<157.0
Mozilla Firefox ESR<153.4
153.4
Mozilla Firefox<157
157
Mozilla Thunderbird<153.4
153.4
debian/firefox
160.0-1
debian/firefox-esr<=140.12.0esr-1~deb12u1, <=140.15.0esr-1~deb13u1
153.7.0esr-1~deb12u1153.7.0esr-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 157
  2. Upgrade

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

    Fixed in 153.4
  3. Upgrade

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

    Fixed in 160.0-1
  4. Upgrade

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

    Fixed in 153.7.0esr-1~deb12u1Fixed in 153.7.0esr-1~deb13u1Fixed in 153.5.1esr-1Fixed in 153.7.0esr-1
  5. 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
  6. Upgrade

    Upgrade Firefox ESR to a version that resolves this vulnerability.

    Fixed in 153.4
  7. Upgrade

    Upgrade Firefox to a version that resolves this vulnerability.

    Fixed in 157
  8. Upgrade

    Upgrade Thunderbird ESR to a version that resolves this vulnerability.

    Fixed in 153.4
  9. Upgrade

    Upgrade Thunderbird to a version that resolves this vulnerability.

    Fixed in 157

Event History

Sep 29, 2026
CVE Published
via Mozilla·12:00 AM
Data Sourced
via Mozilla·12:00 AM
DescriptionSeverityAffected Software
CVE Published
via MITRE·12:35 PM
Data Sourced
via MITRE·12:35 PM
Description
Data Sourced
via NVD·01:17 PM
DescriptionSeverityWeaknessAffected Software

Parent advisories

This vulnerability appears in the following advisories.

Peer vulnerabilities

Found alongside the following vulnerabilities.

Frequently Asked Questions

1

Which Firefox releases contain the fix?

The vulnerability was fixed in Firefox ESR 153.4 and Firefox 157.

2

Is there a documented workaround if upgrading is not immediately possible?

The provided information does not identify a workaround or mitigation other than updating to a fixed Firefox release.

Company

Resources

Contact

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