CVE-2016-0189 is a memory corruption vulnerability in Microsoft Internet Explorer. CISA added it to the Known Exploited Vulnerabilities catalogue on 28 March 2022, which means attackers have used it in real attacks. Organisations running the affected product should apply the vendor fix or mitigation as a priority.
What this vulnerability class means
Memory corruption in a browser is dangerous because it can let hostile web content manipulate execution inside a trusted application. In an Internet Explorer context, that means a normal-looking page, ad, or embedded object can become the delivery mechanism for code execution or a browser crash that is part of a larger exploit chain.
The key security issue is not just that the browser fails, but that the failure happens in software designed to process untrusted content at scale. When a browser memory bug is actively exploited, it usually means the attacker is relying on the user simply visiting or rendering something malicious, which lowers the barrier to initial compromise.
Why this is especially risky in enterprise environments
Browser exploitation is often valuable to attackers because it can provide a foothold on a workstation without requiring a password, a phishing login, or a separate software install. From there, the browser process may be used as a launch point for payload staging, credential theft, or follow-on exploitation if the host is not well segmented or hardened.
For a KEV-listed issue, exposure is operational as well as technical: organisations need to assume the vulnerability is not theoretical and that opportunistic scanning or targeted exploitation may already be in progress. This is why prioritisation should follow the vendor fix and the CISA KEV record rather than waiting for routine patch cycles, and why vulnerability management guidance such as Vulnerability Management Guide is relevant here.
How organisations check exposure and reduce blast radius
Start with a trustworthy asset inventory that shows where the affected browser is installed and whether it is still permitted for business use. If the software is present on endpoints that can reach the internet, exposure is materially higher because the attack path depends on remote content delivery, not local access.
Vendor advisories and the CISA KEV catalogue are the authoritative sources for patch and mitigation details. The practical question is whether the vulnerable software is deployed, whether it is still exposed to untrusted web content, and whether compensating controls can reduce risk until remediation is complete. That is where the broader CVE record in NIST National Vulnerability Database and the official record at CVE Program help anchor the vulnerability identifier and its public tracking.
Detection, remediation, and post-exploitation review
After patching or mitigation, organisations should review whether the endpoint showed signs of browser-driven compromise before the fix was applied. Useful checks include unusual child processes, unexpected script or download activity, suspicious browser crashes, and any later evidence of credential or session theft on the same host.
If exploitation is suspected, assume the browser was only the first step. Review nearby identity material, browser sessions, and any tokens, cookies, or saved credentials that may have been exposed during the compromise window, then correlate with EDR, proxy, and endpoint logs to see whether the attacker moved beyond the browser process.
Risk and Threat Considerations
This type of vulnerability is dangerous because it can convert routine web browsing into an initial access path. The real risk is not only execution inside the browser, but the possibility that the browser becomes a stepping stone to broader endpoint compromise before defenders notice.
Failure mechanism: A malicious page or embedded object triggers memory corruption, which can destabilise the browser process or permit arbitrary code execution under the user’s context.
Impact: Attackers may gain a foothold on the endpoint, steal browser-stored secrets or sessions, and use the compromised machine for follow-on intrusion activity.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
CIS Controls v8, NIST CSF 2.0, 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 | This CVE is a known exploited vulnerability requiring prioritized remediation and exposure tracking. |
| Recommendation — Prioritise remediation using CIS-7 and verify the vulnerable browser is removed or mitigated across the estate. | ||
| NIST CSF 2.0 | GV.RM-01 — Risk Management Strategy | KEV-listed exploitation demands risk-based prioritisation of remediation and compensating controls. |
| Recommendation — Use GV.RM-01 to rank this vulnerability ahead of routine patch work and approve temporary compensating controls. | ||
| NIST SP 800-53 Rev 5 | SI-2 — Flaw Remediation | The issue requires timely remediation of a software flaw in a browser product. |
| RA-5 — Vulnerability Monitoring and Scanning | Exposure checking depends on inventorying and scanning affected endpoints. | |
| Recommendation — Apply SI-2 to track, patch, and verify remediation for the vulnerable browser deployment. Use RA-5 to identify hosts still running the vulnerable browser and confirm remediation status. | ||
| OWASP ASVS | V16 — Security Logging and Error Handling | Post-exploitation review depends on logs and crash/error telemetry that can reveal abuse. |
| Recommendation — Retain and inspect browser, endpoint, and proxy logs to validate whether exploitation occurred. | ||
Practitioner Guidance
Why practitioners should care: Treat KEV-listed browser memory corruption as a high-priority exposure because exploitation is often low-friction and can bypass perimeter controls entirely. Where the browser is still in use, reduce exposure by limiting access to untrusted web content and tightening endpoint control until the affected software is removed or remediated.
Practitioner takeaway: If the vulnerable browser is still present anywhere in the estate, the safest assumption is that it is already part of an active attack surface, not just a maintenance issue.
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Reviewed and updated by the NHIMG editorial team on October 17, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org