CVE-2026-0879: Sandbox escape due to incorrect boundary conditions in the Graphics component

Published Jan 13, 2026
·
Updated

Sandbox escape due to incorrect boundary conditions in the Graphics component. This vulnerability affects Firefox < 147, Firefox ESR < 115.32, and Firefox ESR < 140.7.

Other sources

Sandbox escape due to incorrect boundary conditions in the Graphics component. This vulnerability was fixed in Firefox 147, Firefox ESR 115.32, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7.

— MITRE

Affected Software

10 affected componentsFixes available
Mozilla Firefox ESR<115.32
115.32
Mozilla Firefox<147
147
Mozilla Firefox ESR<140.7
140.7
Mozilla Thunderbird<140.7
140.7
Mozilla Thunderbird<147
147
Mozilla Firefox<115.32.0
Mozilla Firefox<147.0
Mozilla Firefox>=128.0<140.7.0
Mozilla Thunderbird<140.7.0
Mozilla Thunderbird<147.0

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 115.32
  2. Upgrade

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

    Fixed in 147
  3. Upgrade

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

    Fixed in 140.7
  4. Upgrade

    Upgrade Mozilla Firefox to a version that resolves this vulnerability.

    Fixed in 147
  5. Upgrade

    Upgrade Firefox ESR to a version that resolves this vulnerability.

    Fixed in 115.32
  6. Upgrade

    Upgrade Firefox ESR to a version that resolves this vulnerability.

    Fixed in 140.7
  7. Upgrade

    Upgrade Mozilla Thunderbird to a version that resolves this vulnerability.

    Fixed in 147
  8. Upgrade

    Upgrade Thunderbird to a version that resolves this vulnerability.

    Fixed in 140.7

Event History

Jan 13, 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·01:30 PM
Data Sourced
via MITRE·01:30 PM
Description
Data Sourced
via Red Hat·02:02 PM
DescriptionSeverityAffected Software
Data Sourced
via NVD·02:16 PM
DescriptionSeverityWeaknessAffected Software

Parent advisories

This vulnerability appears in the following advisories.

Peer vulnerabilities

Found alongside the following vulnerabilities.

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Frequently Asked Questions

1

What is the severity of CVE-2026-0879?

CVE-2026-0879 is classified as a critical vulnerability due to its potential to allow unauthorized access and impact user security.

2

How do I fix CVE-2026-0879?

To fix CVE-2026-0879, upgrade to Mozilla Firefox version 147, Firefox ESR version 115.32, or version 140.7.

3

What versions of Firefox are affected by CVE-2026-0879?

CVE-2026-0879 affects Firefox versions earlier than 147, and Firefox ESR versions earlier than 115.32 and 140.7.

4

What type of vulnerability is CVE-2026-0879?

CVE-2026-0879 is a sandbox escape vulnerability resulting from incorrect boundary conditions in the Graphics component.

5

Can CVE-2026-0879 be exploited remotely?

Yes, CVE-2026-0879 can potentially be exploited remotely, allowing an attacker to escape the sandbox and execute arbitrary code.

Company

Resources

Contact

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