CVE-2026-6779

Vulnerability

Overview

CVE-2026-6779 is an unspecified issue in the JavaScript Engine component of Firefox and Thunderbird. The vulnerability was addressed in Firefox 150 and Thunderbird 150, as announced in Mozilla Foundation Security Advisories 2026-30 and 2026-33 [1][2]. The exact nature of the bug is not detailed in the public advisories, but it is classified as a security issue with a CVSS v3 score of 5.3 (Medium).

Exploitation

Context

Exploitation

Context

According to the Thunderbird advisory, similar flaws in the product cannot be exploited through email because scripting is disabled when reading mail. However, the vulnerability poses a risk in browser or browser-like contexts [1]. This suggests that exploitation requires an active scripting environment, such as visiting a malicious website or interacting with web content in a browser.

Impact and

Mitigation

The impact of successful exploitation is not explicitly described, but the advisory rates the overall impact as high for the product [1][2]. Users are strongly advised to update to Firefox 150 or Thunderbird version 150 to remediate this vulnerability. No workarounds are mentioned, and the fix is included in the latest stable releases.