CVE-2026-6747
High
Description
Use-after-free in the WebRTC component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.
SeverityHigh
CVSS7.5
Exploit probability—
Product
Mozilla Firefox
PublishedApr 21, 2026
First seenApr 21, 2026
Weakness typeCWE-416Use after freeCWE-825CWE-825
How to fix
Update
- mozilla firefox140.10.0, 150.0 or later
- mozilla thunderbird140.10.0 or later
Vendor advisories
- access.redhat.com/errata/RHSA-2026:19704
- access.redhat.com/errata/RHSA-2026:17690
- access.redhat.com/errata/RHSA-2026:19463
- access.redhat.com/errata/RHSA-2026:10767
- access.redhat.com/errata/RHSA-2026:12285
- access.redhat.com/errata/RHSA-2026:19041
- access.redhat.com/errata/RHSA-2026:19131
- access.redhat.com/errata/RHSA-2026:10766
- access.redhat.com/errata/RHSA-2026:13537
- access.redhat.com/errata/RHSA-2026:19655
- access.redhat.com/errata/RHSA-2026:19465
- access.redhat.com/errata/RHSA-2026:19542
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| mozilla firefox | v < 140.10.0, v < 150.0 | 140.10.0, 150.0 |
| mozilla thunderbird | v < 140.10.0 | 140.10.0 |
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