Is CVE-2010-0806 (Microsoft Internet Explorer Use-After-Free) being exploited in the wild?

By NHI Mgmt Group Editorial Team Updated October 19, 2026 Domain: Threats, Abuse & Incident Response

Yes. CISA added CVE-2010-0806 to its Known Exploited Vulnerabilities catalogue on 20 May 2026, which it does only when there is reliable evidence of active exploitation. CISA has not linked it to known ransomware campaigns. Microsoft Internet Explorer contains an use-after-free vulnerability that could allow remote attackers to execute arbitrary code via vectors involving access to an invalid pointer after the deletion of an object.

Was this really active exploitation, or just a published weakness?

This is an exploitation-status question, not a scoring question. For CVEs, the practical distinction is whether there is evidence of exploitation in the wild, which is what CISA’s KEV catalogue is intended to capture. That makes the answer operationally meaningful: the item should be treated as live attack surface, not a historical browser bug waiting for theoretical abuse.

The vulnerable component here is legacy browser code in Microsoft Internet Explorer, and the use-after-free pattern matters because memory corruption bugs can often be turned into arbitrary code execution when an attacker can shape program state. The key practitioner question is therefore whether your environment still exposes the browser, its rendering engine, or any dependent compatibility mode that preserves the attack path.

Use the vendor advisory and the CISA Known Exploited Vulnerabilities Catalog to confirm the current remediation instructions and any environment-specific constraints. If the browser is still present anywhere in your estate, treat this as a patch and exposure-management problem first, and a browser hardening problem second.

What should you check before you assume you are safe?

Start with exposure confirmation. In practice, that means identifying whether Internet Explorer binaries, compatibility features, embedded web controls, or older enterprise images still exist on any endpoint or server that a user or automation can reach. A CVE can be “old” and still matter if the vulnerable code remains enabled in a long-lived environment.

Then verify whether the affected browsing path is reachable from normal user activity, because exploitability depends on whether a victim can be driven to open malicious content or visit a hostile page. If the attack surface is present only in a confined legacy workflow, the risk is narrower, but not eliminated.

Use authoritative records from the CVE Program and the NIST National Vulnerability Database to cross-check the record, the weakness description, and any metadata that helps you map the issue to your asset inventory. That is especially important when the product is embedded in broader Windows estates rather than maintained as a standalone browser installation.

What does exploitation mean for response and recovery?

If exploitation is confirmed or strongly suspected, the response should go beyond routine patching. Browser exploitation often creates a path to code execution on the endpoint, which means you should think about initial access, local persistence, and whether browser-stored data, sessions, or credentials may have been reachable after compromise.

Legacy browser exploitation also raises a containment issue: if the browser is still required for business compatibility, you may need compensating controls while you remove or disable the vulnerable execution path. That can include limiting who can launch the browser, reducing access to untrusted content, and tightening the systems that still rely on it.

For teams that are triaging many issues at once, FIRST EPSS can help with prioritisation, but in this case KEV status already provides the stronger signal: confirmed exploitation matters more than probability modelling. The response priority should therefore be based on exposure plus exploitation evidence, not on historical age or low perceived novelty.

Risk and Threat Considerations

A browser use-after-free is risky because it can convert ordinary web exposure into arbitrary code execution on the endpoint. When the vulnerable browser path is still reachable, an attacker may only need a lure that causes a user to render malicious content or follow a crafted link.

Failure mechanism: The flaw can free an object and later dereference an invalid pointer, which creates memory corruption conditions that may be shaped into code execution or crash-prone instability.

Impact: Successful exploitation can give an attacker foothold on a user system, enabling credential theft, follow-on payload delivery, or lateral movement if the endpoint is not well contained.

Standards & Framework Alignment

This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.

MITRE ATT&CK addresses the attack and risk surface, while CIS Controls v8, NIST SP 800-53 Rev 5 and OWASP ASVS set the governance and control requirements practitioners need to meet.

Framework	Control / Reference	Relevance
CIS Controls v8	CIS-7 — Continuous Vulnerability Management	KEV-listed browser flaws require asset discovery and timely remediation prioritization.
Recommendation — Prioritise and remediate KEV-listed browser vulnerabilities on exposed assets first.
NIST SP 800-53 Rev 5	RA-5 — Vulnerability Monitoring and Scanning	This question is about confirming exposure and tracking an actively exploited CVE across assets.
	SI-2 — Flaw Remediation	Active exploitation makes patching and compensating remediation the core response.
Recommendation — Scan for Internet Explorer exposure and track the vulnerability to remediation closure. Apply the vendor fix or approved mitigation for the vulnerable browser component.
OWASP ASVS	V13 — Configuration	Legacy browser exposure often persists through configuration and compatibility settings.
Recommendation — Disable or constrain legacy browser components and compatibility modes that preserve the attack path.
MITRE ATT&CK	T1203 — Exploitation for Client Execution	The flaw is a client-side code-execution path triggered through malicious content or interaction.
Recommendation — Map the browser exploit path to client-execution detections and hunt for follow-on activity.

Practitioner Guidance

What to verify: Confirm whether IE or its compatible rendering components are still installed, enabled, or reachable in any production, admin, or kiosk workflow. If yes, treat the environment as exposed until you have proven the vulnerable path is removed or blocked.

Decision rule: If the vulnerable browser path is still needed for business, prioritise isolation and exposure reduction first, then patching or deprecation as the durable fix. If it is not needed, removal is the cleanest risk reduction because it deletes the attack path rather than trying to defend it.

Practitioner takeaway: For KEV-listed browser flaws, the real question is not whether the CVE is old, but whether the vulnerable execution path still exists anywhere an attacker can reach.

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NHIMG Editorial Note
Reviewed and updated by the NHIMG editorial team on October 19, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org