SB20260511100 - Multiple vulnerabilities in Mozilla Thunderbird

Description

This security bulletin contains information about 3 vulnerabilities.

1) Use-after-free (CVE-ID: CVE-2026-8090)

CWE-ID: CWE-416 - Use After Free

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 use-after-free in the DOM: Networking component when processing web content. A remote attacker can trigger the use-after-free with specially crafted content to execute arbitrary code.

User interaction is required to visit a specially crafted website or open a specially crafted URL.

2) Buffer overflow (CVE-ID: CVE-2026-8092)

CWE-ID: CWE-119 - Memory corruption

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 memory corruption when processing web content. A remote attacker can trigger memory corruption using specially crafted content to execute arbitrary code.

Some of the reported bugs showed evidence of memory corruption.

3) Buffer overflow (CVE-ID: CVE-2026-8093)

CWE-ID: CWE-119 - Memory corruption

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 memory corruption when processing web content. A remote attacker can trigger memory corruption using specially crafted content to execute arbitrary code.

Some of the reported bugs showed evidence of memory corruption.

Remediation

Install update from vendor's website.

References

• https://www.mozilla.org/en-US/security/advisories/mfsa2026-43/