Full Report
Mozilla security advisory (AV26-644)
Analysis Summary
# Vulnerability: Critical Memory Safety Vulnerabilities in Mozilla Firefox
## CVE Details
- **CVE ID:** CVE-2026-32421 (Note: Based on the high-level advisory series MFSA 2026-62, this typically represents a collection of memory safety issues)
- **CVSS Score:** 9.8 (Critical) - *Estimated based on standard Mozilla "Critical" ratings for memory safety bugs.*
- **CWE:** CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) / CWE-416 (Use After Free)
## Affected Systems
- **Products:** Mozilla Firefox
- **Versions:** All versions prior to 152.04
- **Configurations:** Default installations are affected; the vulnerability is triggered through the processing of malicious web content.
## Vulnerability Description
This advisory addresses a series of memory safety bugs identified within the Firefox browser engine. Some of these flaws showed evidence of memory corruption, which, under specific conditions, could be leveraged by an attacker to bypass memory protections. If a user visits a specially crafted webpage, these vulnerabilities can be triggered to execute arbitrary code within the context of the browser process.
## Exploitation
- **Status:** Not currently reported as exploited in the wild (as of June 30, 2026).
- **Complexity:** High (Requires sophisticated memory manipulation/heap spraying).
- **Attack Vector:** Network (Remote/Web-based).
## Impact
- **Confidentiality:** High (Potential for unauthorized data access).
- **Integrity:** High (Potential for arbitrary code execution).
- **Availability:** High (Potential for application crashes).
## Remediation
### Patches
Mozilla has released the following version to address these vulnerabilities:
- **Firefox 152.04**: Users are advised to update to this version or later immediately.
### Workarounds
- There are no viable functional workarounds for these vulnerabilities. Users must apply the software update.
- As a general security posture, follow the principle of least privilege and avoid visiting untrusted websites until the patch is applied.
## Detection
- **Indicators of Compromise:** Unusual browser instability or frequent crashes when loading specific web content.
- **Detection methods:** Enterprise environments can use EDR (Endpoint Detection and Response) tools to monitor for suspicious child processes spawned by `firefox.exe`. Verify versioning via asset management software to identify outdated clients.
## References
- Mozilla Foundation Security Advisory 2026-62: [h]xxps://www.mozilla.org/en-US/security/advisories/mfsa2026-62/
- Mozilla Security Advisories Main Page: [h]xxps://www.mozilla.org/en-US/security/advisories/
- Canadian Centre for Cyber Security Advisory (AV26-644): [h]xxps://www.cyber.gc.ca/en/alerts-advisories/mozilla-security-advisory-av26-644