VDB
DEBIAN-CVE-2026-4721
DEBIAN-CVE-2026-4721
PUBLISHED
CVSS 9.800000190734863 CRITICAL
Memory safety bugs present in Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird ESR 140.8, Firefox 148 and Thunderbird 148. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
Risk Scores
CVSS v3.1
9.800000190734863
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Debian:14 | thunderbird | 140.5.0, 1:140.3.0esr-1~deb11u1, 1:140.3.0esr-1~deb12u1 |
| Debian:14 | firefox-esr | 128.14.0esr-1~deb12u1, 128.14.0esr-1~deb11u1, 128.13.0esr-1 |
| Debian:12 | firefox-esr | 128.4.0esr-1, 128.3.1esr-2, 128.3.1esr-1~deb12u1 |
| Debian:11 | thunderbird | 135.0-1, 136.0-1, 137.0-1 |
| Debian:12 | thunderbird | 115.7.0-1, 1:102.11.0-1, 1:102.12.0-1~deb10u1 |
| Debian:11 | firefox-esr | 91.9.0esr-1~deb11u1, 91.9.0esr-1~deb9u1, 91.9.1esr-1 |
| Debian:13 | thunderbird | 140.9.0, 140.9.0, 140.8.0 |
| Debian:13 | firefox-esr | 140.9.0, 140.9.0, 140.8.0 |
Timeline
- Mar 24, 2026 CVE Published
- Apr 28, 2026 CVE Updated