Vulnerability in Mozilla Firefox
CVE-2026-74970
Site isolation issue in the Graphics component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.002 (4.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 4th percentile — 4.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.000
Affected products
Weakness classification (CWE)
Public proof-of-concept exploits
References
- bugzilla.mozilla.org/show_bug.cgi (Permissions Required)
- www.mozilla.org/security/advisories/mfsa2026-74/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2026-77/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2026-78/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2026-80/ (Vendor Advisory)
Frequently asked questions
- What is CVE-2026-74970?
- CVE-2026-74970 is a medium-severity vulnerability in Mozilla Firefox, classified under Origin Validation Error. CVSS score: 5.4/10. Published 2026-08-18.
- How severe is CVE-2026-74970?
- Medium severity. CVSS v3 base score is 5.4 out of 10.
- Is CVE-2026-74970 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.