Integer overflow in Mozilla Firefox
CVE-2026-5732
Incorrect boundary conditions, integer overflow in the Graphics: Text component. This vulnerability was fixed in Firefox 149.0.2, Firefox ESR 140.9.1, Thunderbird 149.0.2, and Thunderbird 140.9.1.
Vulnerability class: Integer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.007 (49.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 50th percentile — 49.8% 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: 0.007 · change: +0.003
Affected products
- Mozilla Firefox — versions 140.9.1, 149.0.2
- Mozilla Thunderbird — versions 140.9.1, 149.0.2
Weakness classification (CWE)
References
- bugzilla.mozilla.org/show_bug.cgi (Permissions Required, Issue Tracking)
- www.mozilla.org/security/advisories/mfsa2026-25/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2026-27/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2026-28/
- www.mozilla.org/security/advisories/mfsa2026-29/
- 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-2026-5732?
- CVE-2026-5732 is a high-severity vulnerability in Mozilla Firefox, classified under Integer Overflow or Wraparound. CVSS score: 8.8/10. Published 2026-04-07.
- How severe is CVE-2026-5732?
- High severity. CVSS v3 base score is 8.8 out of 10.