SB2026060303 - Two remote code execution vulnerabilities in Mozilla Firefox

Description

This security bulletin contains information about 2 vulnerabilities.

1) Out-of-bounds write (CVE-ID: CVE-2026-10701)

CWE-ID: CWE-787 - Out-of-bounds write

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber

The vulnerability allows a remote attacker to execute arbitrary code.

The vulnerability exists due to an out-of-bounds write in the Graphics: Text component when rendering text content. A remote attacker can trigger the issue with specially crafted content to execute arbitrary code.

2) Incorrect calculation (CVE-ID: CVE-2026-10702)

CWE-ID: CWE-682 - Incorrect Calculation

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber

The vulnerability allows a remote attacker to execute arbitrary code.

The vulnerability exists due to improper code generation in the JavaScript Engine: JIT component when processing JavaScript. A remote attacker can supply specially crafted script to execute arbitrary code.

Remediation

Install update from vendor's website.

References

• https://www.mozilla.org/en-US/security/advisories/mfsa2026-54/
• https://bugzilla.mozilla.org/show_bug.cgi?id=2038537
• https://bugzilla.mozilla.org/show_bug.cgi?id=2040903