Vulnerability in Mozilla Firefox
CVE-2026-2768
Sandbox escape in the Storage: IndexedDB component. This vulnerability was fixed in Firefox 148, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 10.0 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.006 (44.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 45th percentile — 44.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.006 · change: +0.002
Affected products
- Mozilla Firefox — versions 140.8, 148
- Mozilla Thunderbird — versions 140.8, 148
Weakness classification (CWE)
References
- bugzilla.mozilla.org/show_bug.cgi (Permissions Required, Issue Tracking)
- www.mozilla.org/security/advisories/mfsa2026-13/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2026-15/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2026-16/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2026-17/ (Vendor Advisory)
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
Frequently asked questions
- What is CVE-2026-2768?
- CVE-2026-2768 is a critical-severity vulnerability in Mozilla Firefox, classified under Improper Access Control. CVSS score: 10.0/10. Published 2026-02-24.
- How severe is CVE-2026-2768?
- Critical severity. CVSS v3 base score is 10.0 out of 10.