Information disclosure in Mozilla Thunderbird - CVE-2026-0818
Published: January 29, 2026
Vulnerability identifier: #VU122117
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-0818
CWE-ID: CWE-200
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Mozilla
Affected software:
Mozilla Thunderbird
Mozilla Thunderbird
Detailed vulnerability description
The vulnerability allows a remote attacker to gain access to potentially sensitive information.
The vulnerability exists due to the way CSS is handled within the application. A remote attacker can exfiltrate content from partially encrypted emails when allowing remote content.
How to mitigate CVE-2026-0818
Install updates from vendor's website.