CVE-2026-6754

high

Description

Use-after-free in the JavaScript Engine component. This vulnerability was fixed in Firefox 150, Firefox ESR 115.35, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.

References

https://www.mozilla.org/security/advisories/mfsa2026-34/

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

https://www.mozilla.org/security/advisories/mfsa2026-32/

https://www.mozilla.org/security/advisories/mfsa2026-31/

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

https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-6754.json

https://bugzilla.redhat.com/show_bug.cgi?id=2460075

https://bugzilla.mozilla.org/show_bug.cgi?id=2027541

https://access.redhat.com/security/cve/CVE-2026-6754

https://access.redhat.com/errata/RHSA-2026:19704

https://access.redhat.com/errata/RHSA-2026:19655

https://access.redhat.com/errata/RHSA-2026:19542

https://access.redhat.com/errata/RHSA-2026:19469

https://access.redhat.com/errata/RHSA-2026:19468

https://access.redhat.com/errata/RHSA-2026:19467

https://access.redhat.com/errata/RHSA-2026:19466

https://access.redhat.com/errata/RHSA-2026:19465

https://access.redhat.com/errata/RHSA-2026:19464

https://access.redhat.com/errata/RHSA-2026:19463

https://access.redhat.com/errata/RHSA-2026:19462

https://access.redhat.com/errata/RHSA-2026:19461

https://access.redhat.com/errata/RHSA-2026:19348

https://access.redhat.com/errata/RHSA-2026:19201

https://access.redhat.com/errata/RHSA-2026:19131

https://access.redhat.com/errata/RHSA-2026:19041

https://access.redhat.com/errata/RHSA-2026:17690

https://access.redhat.com/errata/RHSA-2026:17689

https://access.redhat.com/errata/RHSA-2026:17688

https://access.redhat.com/errata/RHSA-2026:17687

https://access.redhat.com/errata/RHSA-2026:17477

https://access.redhat.com/errata/RHSA-2026:15892

https://access.redhat.com/errata/RHSA-2026:13537

https://access.redhat.com/errata/RHSA-2026:12285

https://access.redhat.com/errata/RHSA-2026:10767

https://access.redhat.com/errata/RHSA-2026:10766

https://access.redhat.com/errata/RHSA-2026:10757

Details

Source: Mitre, NVD

Published: 2026-04-21

Updated: 2026-06-30

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:H/PR:N/UI:R/S:U/C:H/I:H/A:H

Severity: High

EPSS

EPSS: 0.00053