Full Report
Multiple vulnerabilities have been discovered in Mozilla products, the most severe of which could allow for arbitrary code execution. Mozilla Firefox is a web browser used to access the Internet.Mozilla Firefox ESR is a version of the web browser intended to be deployed in large organizations.Successful exploitation of the most severe of these vulnerabilities could allow for arbitrary code execution. Depending on the privileges associated with the user an attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. Users whose accounts are configured to have fewer user rights on the system could be less impacted than those who operate with administrative user rights.
Analysis Summary
# Vulnerability: Multiple Mozilla Product Vulnerabilities Leading to Arbitrary Code Execution
## CVE Details
- **CVE ID:** CVE-2026-8946, CVE-2026-8388, CVE-2026-8947, CVE-2026-8391, CVE-2026-8401, CVE-2026-8975, CVE-2026-8945, CVE-2026-8948, CVE-2026-8973, CVE-2026-8706 (and others)
- **CVSS Score:** Not explicitly provided by the source, but rated as **High Risk** for government and business entities.
- **CWE:** Multiple, including CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer), CWE-416 (Use After Free), CWE-190 (Integer Overflow), and CWE-284 (Improper Access Control).
## Affected Systems
- **Products:**
- Mozilla Firefox
- Mozilla Firefox ESR (Extended Support Release)
- Mozilla Firefox for iOS/Android
- Mozilla Firefox Focus for Android
- **Versions:**
- Firefox versions prior to 151
- Firefox for iOS versions prior to 151.0
- Firefox ESR versions prior to 140.11
- Firefox ESR versions prior to 115.36
- **Configurations:** The impact is significantly higher for users operating with administrative rights.
## Vulnerability Description
This advisory covers a wide range of security flaws across several Mozilla components:
- **Memory Corruption:** Incorrect boundary conditions in the JavaScript Engine (CVE-2026-8388) and Audio/Video components (CVE-2026-8946).
- **Use-After-Free:** Discovered in the DOM (CVE-2026-8947) and Disability Access APIs (CVE-2026-8953).
- **Sandbox Escapes:** Identified in the Profile Backup component (CVE-2026-8401), Security component (CVE-2026-8958), and mobile versions.
- **Logic Flaws:** Same-origin policy bypasses in Networking and DOM components (CVE-2026-8948, CVE-2026-8950).
## Exploitation
- **Status:** Not currently reported as exploited in the wild.
- **Complexity:** Medium to High (Depending on the specific flaw, though most browser exploits require chaining).
- **Attack Vector:** Network (Drive-by Compromise).
## Impact
Successful exploitation of the most severe flaws allows for **Arbitrary Code Execution (ACE)**.
- **Confidentiality:** High (Attacker can view/delete data and sensitive user info).
- **Integrity:** High (Attacker can install programs and change data).
- **Availability:** High (Attacker can delete data or cause Denial of Service).
## Remediation
### Patches
Mozilla has released the following updated versions to address these issues:
- **Firefox:** Upgrade to version 151 or later.
- **Firefox for iOS:** Upgrade to version 151.0 or later.
- **Firefox ESR:** Upgrade to version 140.11 or 115.36 (depending on the branch).
### Workarounds
- Operate using an account with **least privilege** (non-administrative) to limit the impact of code execution.
- Restrict web browsing to trusted sites only until updates are applied.
## Detection
- **Indicators of Compromise:** Unusual browser crashes, unauthorized creation of new user accounts, or unexpected outbound network traffic from browser processes.
- **Detection methods:** End-point Detection and Response (EDR) tools can monitor for unusual child processes (e.g., `firefox.exe` spawning `cmd.exe` or `powershell.exe`).
## References
- **Vendor Advisories:**
- hxxps://www.mozilla[.]org/en-US/security/advisories/mfsa2026-46/
- hxxps://www.mozilla[.]org/en-US/security/advisories/mfsa2026-47/
- hxxps://www.mozilla[.]org/en-US/security/advisories/mfsa2026-48/
- hxxps://www.mozilla[.]org/en-US/security/advisories/mfsa2026-49/
- **CVE Database:**
- hxxps://cve.mitre[.]org/cgi-bin/cvename.cgi?name=CVE-2026-8946
- hxxps://cve.mitre[.]org/cgi-bin/cvename.cgi?name=CVE-2026-8975