Integer overflow in Mozilla Firefox

CVE-2025-10533

Integer overflow in the SVG component. This vulnerability was fixed in Firefox 143, Firefox ESR 115.28, Firefox ESR 140.3, Thunderbird 143, and Thunderbird 140.3.

Vulnerability class: Integer Overflow

EPSS: 0.007 (48.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-10533?
CVE-2025-10533 is a high-severity vulnerability in Mozilla Firefox, classified under Integer Overflow or Wraparound. CVSS score: 8.8/10. Published 2025-09-16.
How severe is CVE-2025-10533?
High severity. CVSS v3 base score is 8.8 out of 10.
Is CVE-2025-10533 known to be exploited?
6 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.