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.Mozilla Thunderbird is an email client.Mozilla Thunderbird ESR is a version of the email client 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 Memory Safety and Boundary Condition Flaws
## CVE Details
- **CVE ID:** CVE-2026-7322, CVE-2026-7323, CVE-2026-7324 (Memory Safety); CVE-2026-7320 (Information Disclosure); CVE-2026-7321 (Sandbox Escape).
- **CVSS Score:** Not explicitly provided, but categorized as **Critical/High** severity based on the potential for Arbitrary Code Execution (ACE).
- **CWE:** CWE-119 (Memory Corruption) / CWE-125 / CWE-787 (Boundary Issues).
## Affected Systems
- **Products:** Mozilla Firefox, Firefox ESR, Thunderbird, and Thunderbird ESR.
- **Versions:**
- Firefox: Prior to 150.0.1
- Firefox ESR: Prior to 140.10.1 and 115.35.1
- Thunderbird: Prior to 150.0.1
- Thunderbird ESR: Prior to 140.10.1
- **Configurations:** Systems where users operate with high administrative privileges are at specific risk for full system compromise.
## Vulnerability Description
This advisory covers several classes of security flaws:
1. **Memory Safety Bugs (CVE-2026-7322, 7323, 7324):** Various internal engine flaws that can be exploited to corrupt memory, potentially leading to arbitrary code execution.
2. **Boundary Condition Errors (CVE-2026-7320):** Affects the Audio/Video component, leading to unauthorized information disclosure.
3. **Sandbox Escape (CVE-2026-7321):** An issue in WebRTC boundary conditions that allows an attacker to bypass the browser's security sandbox.
## Exploitation
- **Status:** Not currently reported as exploited in the wild.
- **Complexity:** Medium (Typical for memory safety and sandbox escapes).
- **Attack Vector:** Network (Drive-by compromise via malicious websites or emails).
## Impact
- **Confidentiality:** High (Data theft and information disclosure).
- **Integrity:** High (Modification of data and account creation).
- **Availability:** High (System takeover and program installation).
## Remediation
### Patches
Mozilla has released the following versions to address these issues:
- **Firefox:** 150.0.1
- **Firefox ESR:** 140.10.1 and 115.35.1
- **Thunderbird:** 150.0.1
- **Thunderbird ESR:** 140.10.1
### Workarounds
- **Principle of Least Privilege:** Run browsers and email clients under non-privileged user accounts to limit the scope of a successful ACE exploit.
- **Restrict Unnecessary Features:** Disable or restrict WebRTC and legacy media codecs if not required in enterprise environments.
## Detection
- **Indicators of Compromise:** Unusual browser crashes followed by unauthorized outbound network connections or the creation of unexpected local user accounts.
- **Detection Methods:**
- Use Vulnerability Management Scanners to identify outdated Firefox/Thunderbird binaries.
- Monitor for MITRE ATT&CK Tactic **TA0001** (Initial Access) and Technique **T1189** (Drive-by Compromise).
## References
- **Mozilla Security Advisories:** hxxps://www.mozilla[.]org/en-US/security/advisories/
- **Specific Advisory:** hxxps://www.mozilla[.]org/en-US/security/advisories/mfsa2026-35/
- **CVE Mitre:** hxxps://cve.mitre[.]org/cgi-bin/cvename.cgi?name=CVE-2026-7322