CVE-2026-118008
Description
A flaw was found in Firefox and Thunderbird. The Mozilla Foundation's Security Advisory describes the following issue: Privilege escalation in the DOM: Navigation component
Statement
Red Hat Product Security rates the severity of this flaw as determined by the Mozilla Foundation Security Advisory.
Mitigation
--- CME Mitigation Guidance (2026-11-02) ---
Disclaimer: The following mitigation solutions are provided as a courtesy, pending the application of an official patch. This content was generated utilizing AI tools in conjunction with data from https://cmetaxonomy.org. Customers are advised to independently evaluate and test these temporary mitigations within their own infrastructure.
The highest-value action is to enforce strict privilege boundary checks during DOM navigation to prevent script execution from escalating into higher-privileged contexts: upgrade to Firefox 159, Thunderbird 159, which corrects privilege management within the DOM Navigation component to block unprivileged execution in higher-privileged contexts, closing all 2 injection vectors (crafted web page navigation, DOM navigation manipulation). Until patched, this is only a concern on all platforms running Firefox or Thunderbird with JavaScript execution enabled — Thunderbird email viewing where scripting is disabled by default are unaffected — so restrict visiting untrusted websites and disable JavaScript execution in web-browsing contexts. These controls limit blast radius and contain exploitation, but they do not fix the underlying improper privilege management flaw — apply the upstream patch to fully remediate.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.5 | N/A | 8.8 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | High | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | Required | N/A | Required |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Access Control
Technical Impact: Gain Privileges or Assume Identity
A user can assume the identity of another user with separate privileges in another context. This will give the user unauthorized access that may allow them to acquire the access information of other users.
Frequently Asked Questions
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