Is CVE-2018-0824 (Microsoft COM for Windows Deserialization of Untrusted Data) being exploited in the wild?

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

Yes. CISA added CVE-2018-0824 to its Known Exploited Vulnerabilities catalogue on 5 August 2024, which it does only when there is reliable evidence of active exploitation. CISA has not linked it to known ransomware campaigns. Microsoft COM for Windows contains a deserialization of untrusted data vulnerability that allows for privilege escalation and remote code execution via a specially crafted file or script.

What “being exploited in the wild” means for this CVE

For a CVE like CVE-2018-0824, the practical question is not whether the flaw exists in theory, but whether defenders should treat it as an active exposure. CISA’s KEV inclusion is the clearest signal that exploitation has been observed, so exposure should be handled as an incident-ready vulnerability rather than a routine backlog item. The relevant response posture is informed by Zero-Day and Exploited Vulnerabilities Guide.

Because the issue is a deserialization weakness in Microsoft COM for Windows, the useful operational question is where that code path is reachable in your environment. If an affected system can receive attacker-controlled files or scripts, the vulnerability moves from theoretical to actionable, especially when the application context grants elevated privileges. In practice, this is the kind of flaw that justifies immediate inventory review and prioritised remediation, consistent with the broader approach in the Vulnerability Management Guide.

For defenders, “in the wild” also means you should assume exploit attempts may already have occurred before patching. That shifts the focus from simple exposure confirmation to blast-radius assessment: identify systems that can process untrusted content, determine whether those systems run with privileged service contexts, and treat remote code execution potential as a material security outcome rather than a theoretical one. The deserialization mechanics themselves are covered in the Insecure Deserialisation Guide.

How to validate exposure and respond to active exploitation

Validation starts with confirming whether any Windows hosts in scope can actually invoke the affected COM deserialization path. That means checking software inventory, reachable workflows, and any application or script logic that accepts external input and passes it into the vulnerable component. Once confirmed, the priority is to apply the vendor fix or approved mitigation on every exposed system, then verify that the vulnerable path is no longer reachable from normal business workflows.

If patching must wait, reduce exposure by restricting who can reach the affected systems, limiting file and script ingestion paths, and isolating the hosts that are most likely to process attacker-controlled input. Where business constraints delay remediation, compensating controls should be treated as temporary risk reduction, not as a substitute for fixing the vulnerability. The most relevant external references for version and remediation details are the CISA Known Exploited Vulnerabilities Catalog, the CVE Program, and the NIST National Vulnerability Database.

After remediation, hunt for evidence of prior compromise rather than assuming the patch closes the story. Review process creation, script execution, unusual child processes, privilege changes, and any suspicious file handling around the affected hosts. If the vulnerable path exposed elevated execution context, reset any credentials or tokens that may have been accessible from those systems, and investigate lateral movement paths if the host had broad network reach.

Why this vulnerability is operationally serious

Deserialization flaws are high impact because they can convert a data-handling bug into code execution, and in this case the privilege escalation angle makes the failure more dangerous. A specially crafted file or script can become an execution vehicle, which means the attacker does not need a complex interaction chain once they can reach the input point. The result is a compact attack path from untrusted input to system-level compromise.

That combination also makes detection harder than many teams expect. A malicious payload may look like ordinary content until the vulnerable parser processes it, so exploit success can be buried inside normal operational traffic. If the affected service runs with elevated rights, compromise can extend beyond a single application and become a foothold for broader access on the host and across adjacent systems.

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 NIST CSF 2.0, NIST SP 800-53 Rev 5, CIS Controls v8 and OWASP ASVS set the governance and control requirements practitioners need to meet.

Framework	Control / Reference	Relevance
NIST CSF 2.0	ID.RA-01 — Asset Vulnerabilities Identified	Active exploitation makes exposure identification central to response planning.
Recommendation — Identify exposed Windows hosts and prioritize those with reachable deserialization paths.
NIST SP 800-53 Rev 5	SI-2 — Flaw Remediation	The question is about an exploited software flaw needing prompt correction and verification.
Recommendation — Apply SI-2 to remediate the vulnerability and verify the fix across affected systems.
CIS Controls v8	CIS-7 — Continuous Vulnerability Management	KEV-listed exploitation requires prioritized vulnerability handling and exposure tracking.
Recommendation — Use CIS-7 to prioritize, remediate, and validate exposure to actively exploited vulnerabilities.
MITRE ATT&CK	T1203 — Exploitation for Client Execution	A crafted file or script causing code execution maps to exploit-based execution behavior.
Recommendation — Map the exploit path to T1203 and hunt for execution spawned from untrusted content.
OWASP ASVS	V15 — Secure Coding and Architecture	Deserialization flaws are architecture and input-handling weaknesses that require secure design controls.
Recommendation — Review input-handling and deserialization boundaries under V15 to prevent code execution from untrusted data.

Practitioner Guidance

What to prioritise: Treat CISA KEV inclusion as the trigger for immediate action, not as a reporting detail. Prioritise any host that accepts external files or scripts, any system running with elevated rights, and any environment where the vulnerable COM path is exposed to business workflows.

What to verify: Confirm that the vulnerable code path is no longer reachable after remediation, and retain evidence of patching, mitigation, and post-fix validation. If you cannot verify reachability, assume the system is still materially exposed.

Decision rule: If the host may have processed malicious input before the fix, perform compromise assessment before declaring the issue closed. When the vulnerability could have exposed privileged execution, rotate or reissue credentials only after you have mapped the likely access scope, so you do not miss a broader compromise window.

Practitioner takeaway: For an actively exploited Windows deserialization flaw, the right response is to combine rapid remediation with compromise hunting, because patching alone does not tell you whether the attacker already used the opening.

Deepen Your Knowledge

Free weekly newsletter

Subscribe to the NHI & AI Identity Journal

The latest on NHI and Agentic AI security – articles, research, breaches, news and events every week.

Bonus 33% off our NHI Course when you subscribe.

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