Auth bypass in Mozilla Firefox

CVE-2025-0237

The WebChannel API, which is used to transport various information across processes, did not check the sending principal but rather accepted the principal being sent. This could have led to privilege escalation attacks. This vulnerability was fixed in Firefox 134, Firefox ESR 128.6, Thunderbird 134, and Thunderbird 128.6.

Vulnerability class: Broken Access Control

EPSS: 0.006 (45.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-0237?
CVE-2025-0237 is a medium-severity vulnerability in Mozilla Firefox, classified under Incorrect Authorization. CVSS score: 5.4/10. Published 2025-01-07.
How severe is CVE-2025-0237?
Medium severity. CVSS v3 base score is 5.4 out of 10.