Full Report
Multiple vulnerabilities have been discovered in Mozilla Firefox, the most severe of which could allow for arbitrary code execution. Mozilla Firefox is a web browser used to access the Internet. 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 Vulnerabilities in Mozilla Firefox (March 2026)
## CVE Details
- **CVE ID:** CVE-2026-3845, CVE-2026-3846, CVE-2026-3847
- **CVSS Score:** Not explicitly provided in advisory (Severity: **High/Critical**)
- **CWE:**
- CWE-122 (Heap-based Buffer Overflow)
- CWE-346 (Origin Validation Error)
- CWE-119 (Memory Corruption)
## Affected Systems
- **Products:** Mozilla Firefox
- **Versions:** All versions prior to 148.0.2
- **Configurations:** Systems where Firefox is used for internet browsing; risk is elevated for users operating with administrative privileges.
## Vulnerability Description
Mozilla Firefox is affected by multiple security flaws:
* **CVE-2026-3845:** A heap buffer overflow exists in the Audio/Video handling component. This could be triggered by processing specifically crafted media content.
* **CVE-2026-3846:** A Same-Origin Policy (SOP) bypass exists within the CSS Parsing and Computation component, potentially allowing a malicious site to access data from another domain.
* **CVE-2026-3847:** General memory safety bugs (memory corruption) identified and fixed in the core engine.
## Exploitation
- **Status:** Not exploited in the wild (as of March 10, 2026); No PoC currently mentioned.
- **Complexity:** Medium
- **Attack Vector:** Network (Remote/Drive-by Compromise)
## Impact
- **Confidentiality:** High (Ability to view data and bypass SOP)
- **Integrity:** High (Ability to change/delete data and install programs)
- **Availability:** High (Potential for system crashes or account takeover)
## Remediation
### Patches
- Update to **Mozilla Firefox 148.0.2** or later immediately.
### Workarounds
- **Principle of Least Privilege:** Operate the browser using a standard user account rather than an administrative account to limit the scope of a potential compromise.
- **Restricted Access:** Ensure only fully supported and updated browsers are used within the enterprise environment.
## Detection
- **Indicators of Compromise:** Unusual browser crashes during media playback, unauthorized program installations, or unexpected creation of new user accounts.
- **Detection methods and tools:**
- Monitor for network traffic to known malicious domains (Drive-by compromise detection).
- Use Endpoint Detection and Response (EDR) tools to identify unauthorized child processes spawned by `firefox.exe`.
- Vulnerability scanners to identify outdated versions of Firefox (prior to 148.0.2).
## References
- hxxps://www.mozilla.org/en-US/security/advisories/mfsa2026-19/
- hxxps://www.cve.org/CVERecord?id=CVE-2026-3845
- hxxps://www.cve.org/CVERecord?id=CVE-2026-3846
- hxxps://www.cve.org/CVERecord?id=CVE-2026-3847
- hxxps://www.cisecurity.org/advisory/multiple-vulnerabilities-in-mozilla-firefox-could-allow-for-arbitrary-code-execution_2026-022