CVE-2026-4729

CWE-120 — Classic Buffer OverflowCWE-82510 documents8 sources
Severity
9.8CRITICAL
EPSS
0.0%
top 94.65%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
2
Mozilla FirefoxMozilla Thunderbird
Timeline
PublishedMar 24

Description

Memory safety bugs present in 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 affects Firefox < 149 and Thunderbird < 149.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitability: 3.9 | Impact: 5.9

Affected Packages4 packages

▶CVEListV5mozilla/firefoxunspecified — 149
▶NVDmozilla/firefox< 149.0
▶CVEListV5mozilla/thunderbirdunspecified — 149
▶NVDmozilla/thunderbird< 149.0

🔴Vulnerability Details

3
OSV
CVE-2026-4729: Memory safety bugs present in Firefox 148 and Thunderbird 148↗2026-03-24
▶
CVEList
Memory safety bugs fixed in Firefox 149 and Thunderbird 149↗2026-03-24
▶
GHSA
GHSA-xh4v-qr89-3hj3: Memory safety bugs present in Firefox 148 and Thunderbird 148↗2026-03-24
▶

📋Vendor Advisories

4
Red Hat
firefox: Memory safety bugs fixed in Firefox 149 and Thunderbird 149↗2026-03-24
▶
Debian
CVE-2026-4729: firefox - Memory safety bugs present in Firefox 148 and Thunderbird 148. Some of these bug...↗2026
▶
Mozilla
Mozilla Foundation Security Advisory 2026-20: CVE-2026-4729↗
▶
Mozilla
Mozilla Foundation Security Advisory 2026-23: CVE-2026-4729↗
▶

🕵️Threat Intelligence

1
Wiz
CVE-2026-4729 Impact, Exploitability, and Mitigation Steps | Wiz↗
▶
CVE-2026-4729 (CRITICAL CVSS 9.8) | Memory safety bugs present in Firef | cvebase.io