VDB
GHSA-mmvq-h6g9-8h39
GHSA-mmvq-h6g9-8h39
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 affects Firefox < 149, Firefox ESR < 115.34, and Firefox ESR < 140.9.
Risk Scores
CVSS 3.1
9.800000190734863
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Timeline
- Mar 24, 2026 CVE Published
- Jun 30, 2026 CVE Updated
- Aug 6, 2026 Distribution Patch
- Aug 6, 2026 Distribution Patch
- Aug 6, 2026 Distribution Patch
- Aug 6, 2026 Distribution Patch
- Aug 6, 2026 Distribution Patch
- Aug 6, 2026 Distribution Patch
- Aug 6, 2026 Distribution Patch
- Aug 6, 2026 Distribution Patch
- Aug 6, 2026 Distribution Patch
- Aug 6, 2026 Distribution Patch
References
- https://bugzilla.mozilla.org/buglist.cgi?bug_id=2013762%2C2015291%2C2016591%2C2016661%2C2016664%2C2017303%2C2017894%2C2018090%2C2018196%2C2018379%2C2019112%2C2022090%2C2022243%2C2022351%2C2022478%2C2022676 url
- https://www.mozilla.org/security/advisories/mfsa2026-20 url
- https://nvd.nist.gov/vuln/detail/CVE-2026-4721 advisory
- https://access.redhat.com/errata/RHSA-2026:5930 url
- https://access.redhat.com/errata/RHSA-2026:8287 url
- https://access.redhat.com/errata/RHSA-2026:8288 url
- https://access.redhat.com/errata/RHSA-2026:8289 url
- https://access.redhat.com/errata/RHSA-2026:8290 url
- https://access.redhat.com/errata/RHSA-2026:8315 url
- https://access.redhat.com/errata/RHSA-2026:8427 url
- https://access.redhat.com/errata/RHSA-2026:8850 url
- https://access.redhat.com/security/cve/CVE-2026-4721 url
- https://bugzilla.redhat.com/show_bug.cgi?id=2450711 url
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4721.json url
- https://www.mozilla.org/security/advisories/mfsa2026-21 url
- https://www.mozilla.org/security/advisories/mfsa2026-22 url
- https://www.mozilla.org/security/advisories/mfsa2026-23 url
- https://www.mozilla.org/security/advisories/mfsa2026-24 url
- https://access.redhat.com/errata/RHSA-2026:5931 url
- https://access.redhat.com/errata/RHSA-2026:5932 url
…and 15 more