What is CVE-2026-0888?

CVE-2026-0888 is a medium-severity vulnerability in Mozilla Firefox, classified under Information Disclosure. CVSS score: 5.3/10. Published 2026-01-13.

How severe is CVE-2026-0888?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Information disclosure in Mozilla Firefox

CVE-2026-0888

Information disclosure in the XML component. This vulnerability was fixed in Firefox 147 and Thunderbird 147.

Vulnerability class: Information Disclosure

EPSS: 0.003 (23.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.

Affected products

Mozilla Firefox — versions 147
Mozilla Thunderbird — versions 147

Weakness classification (CWE)

CWE-200 — Information Disclosure

References

security@mozilla.org (Permissions Required)
security@mozilla.org (Vendor Advisory)
security@mozilla.org (Vendor Advisory)

Frequently asked questions

What is CVE-2026-0888?: CVE-2026-0888 is a medium-severity vulnerability in Mozilla Firefox, classified under Information Disclosure. CVSS score: 5.3/10. Published 2026-01-13.
How severe is CVE-2026-0888?: Medium severity. CVSS v3 base score is 5.3 out of 10.