Is CVE-2026-6786 actively exploited?

CVE-2026-6786 has no public evidence of in-the-wild exploitation as of 2026-04-26.

What is the CVSS score for CVE-2026-6786?

CVE-2026-6786 has a CVSS score of 8.1 (HIGH severity). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.

How do I patch CVE-2026-6786?

Patch guidance is available from Mozilla security advisories. CVEDatabase generates AI-assisted remediation guidance on demand for CVE-2026-6786.

Which products are affected by CVE-2026-6786?

1 product: Mozilla Refer to Description.

Fix CVE-2026-6786 - HIGH Mozilla Refer to Description

Description

Memory safety bugs present in Firefox ESR 140.9, Thunderbird ESR 140.9, Firefox 149 and Thunderbird 149. 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 was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.

CVSS Metrics

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector: network
Complexity: high
Privileges: none
User Action: none
Scope: unchanged
Confidentiality: high
Integrity: high
Availability: high
Weaknesses: CWE-125 · Out-of-bounds Read CWE-416 · Use After Free CWE-787 · Out-of-bounds Write

Metadata

Primary Vendor: MOZILLA
Published: 4/26/2026
Last Modified: 4/26/2026
Source: NIST NVD
Note: Verify all details with official vendor sources before applying patches.

CVE-2026-6786

Description

CVSS Metrics

Metadata

Affected Products

Remediation Guidance

Executive Summary