CVE-2026-6779 - Other issue in the JavaScript Engine component

MEDIUM

Other issue in the JavaScript Engine component

Published Apr 21, 2026

5.3

MEDIUM

CVSS 3.1

EPSS 0.34%

Other issue in the JavaScript Engine component. This vulnerability was fixed in Firefox 150 and Thunderbird 150.

Product	Package	State	Advisory
Red Hat Enterprise Linux 10	rhel10/thunderbird-flatpak	Not affected	n/a
Red Hat Enterprise Linux 10	thunderbird	Not affected	n/a
Red Hat Enterprise Linux 6	thunderbird	Not affected	n/a
Red Hat Enterprise Linux 7	thunderbird	Not affected	n/a
Red Hat Enterprise Linux 8	thunderbird	Not affected	n/a
Red Hat Enterprise Linux 9	thunderbird	Not affected	n/a

Red Hat statement

Red Hat Product Security rates the severity of this flaw as determined by the Mozilla Foundation Security Advisory.

Weaknesses (3)

CWE-119

Buffer Overflow

CWE-20

Improper Input Validation

CWE-79

Cross-site Scripting (XSS)

Link	Providers	Tags
https://access.redhat.com/security/cve/CVE-2026-6779		Vendor Advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=2023343		Permissions Required
https://bugzilla.redhat.com/show_bug.cgi?id=2460090		Issue Tracking
https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-24120		Advisory
https://nvd.nist.gov/vuln/detail/CVE-2026-6779
https://www.cve.org/CVERecord?id=CVE-2026-6779
https://www.mozilla.org/security/advisories/mfsa2026-30/		Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-33/		Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-33/#CVE-2026-6779