CVE-2026-6758

high

Description

Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 150 and Thunderbird 150.

References

https://www.securityweek.com/claude-mythos-finds-271-firefox-vulnerabilities/

https://www.mozilla.org/security/advisories/mfsa2026-33/

https://www.mozilla.org/security/advisories/mfsa2026-30/

https://bugzilla.mozilla.org/show_bug.cgi?id=2013619

Details

Source: Mitre, NVD

Published: 2026-04-21

Updated: 2026-04-22

Risk Information

CVSS v2

Base Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C

Severity: High

CVSS v3

Base Score: 7.5

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Severity: High

EPSS

EPSS: 0.00038