Critical Use‑After‑Free in Mozilla Firefox (CVE‑2022‑26485) Enables Remote Code Execution
What It Is
Mozilla Firefox contains a use‑after‑free flaw in its XSLT parameter processing logic. The memory‑corruption bug can be triggered by a maliciously crafted web page, allowing an attacker to execute arbitrary code in the context of the vulnerable browser.
Exploitability
The vulnerability is rated Critical (CVSS 9.8). Public proof‑of‑concept code has been released, and the exploit does not require user interaction beyond visiting a malicious site. No known active exploitation campaigns have been reported, but the ease of exploitation warrants immediate remediation.
Affected Products
- Vendor: Mozilla
- Product: Firefox (all versions prior to the security update released on 2022‑12‑13)
Why It Matters for Compliance & Audit Readiness
A compromised browser can become a foothold for lateral movement, data exfiltration, and ransomware—events that directly impact control‑based frameworks such as NIST CSF, ISO 27001, and PCI‑DSS. Demonstrating timely patch management and vendor‑risk monitoring satisfies audit expectations for:
- Vendor‑Management Controls – Evidence that third‑party software is continuously assessed and updated.
- Access Controls – Preventing unauthorized code execution maintains the integrity of endpoint access rights.
Documenting the patch cycle, capturing version inventories, and linking remediation to the relevant control mappings creates a defensible audit trail and reinforces an organization’s trust posture.
Recommended Actions
- Verify the Firefox version on all endpoints; any version earlier than 102.5.1 is vulnerable.
- Deploy the Mozilla security update (or enforce automatic updates) through your patch‑management system.
- Update your asset inventory and map the remediation to the “Patch Management” control in your governance framework.
- Capture screenshots or logs of the updated version as evidence for audit readiness.
- Review web‑filtering rules to block known malicious XSLT payloads as a defense‑in‑depth measure.
Source: CISA KEV – CVE‑2022‑26485