CVE-2019-0676 is an information disclosure vulnerability in Microsoft Internet Explorer. CISA added it to the Known Exploited Vulnerabilities catalogue on 23 May 2022, which means attackers have used it in real attacks. An information disclosure vulnerability exists when Internet Explorer improperly handles objects in memory.
What the vulnerability means
CVE-2019-0676 is an information disclosure flaw in Microsoft Internet Explorer, so the security issue is not code execution by itself but unintended exposure of data from memory. That matters because browser memory can contain content from the current session, nearby page activity, or other sensitive runtime state.
Information disclosure bugs in a browser are dangerous because they can reduce the attacker’s work needed for follow-on exploitation. Even when the first impact is limited to leaking data, that leak can still help an adversary build a stronger chain for phishing, session theft, user targeting, or a later exploit against the same host or user.
Why this class of browser flaw is risky
Internet Explorer is part of the client-side attack surface, so a memory-handling weakness can be reached through ordinary web use rather than privileged access. In practice, disclosure bugs are often valuable because they expose details that should remain hidden, such as addresses, object contents, or other memory-derived information that can support exploitation.
The danger is amplified when users browse with active credentials, internal applications, or sensitive business data open in the same session. A disclosure flaw may not look dramatic at first, but it can still create exposure that is difficult to notice until the data has already been used elsewhere.
How organisations assess exposure and reduce blast radius
Exposure review starts with knowing which endpoints still have Internet Explorer available, how broadly it is enabled, and whether it is reachable from user workflows or legacy applications. Organisations should verify the affected browser footprint through asset inventory, browser configuration review, and current vendor guidance, then prioritise systems that are exposed to untrusted web content.
For background on how teams prioritise and track exploited vulnerabilities, see NIST National Vulnerability Database and the official CVE Program. For a practical prioritisation workflow that treats KEV-listed issues as urgent, Vulnerability Management Guide explains how to combine inventory, exposure and remediation tracking.
Remediation, detection and compromise review
The preferred response is to apply the vendor fix and remove or restrict exposed legacy browser use wherever possible. If patching is delayed, organisations should narrow access to affected endpoints, reduce exposure to untrusted content, and apply compensating controls that limit user interaction with legacy browser paths.
Detection should not stop at patch deployment. Teams should review whether the vulnerable browser was used during the exposure window, whether suspicious downloads or redirects occurred, and whether there are signs that memory disclosure was followed by credential abuse or lateral activity. FIRST is a useful reference point for coordinated incident handling when a vulnerability has been actively exploited.
Risk and Threat Considerations
This kind of flaw is attractive to attackers because information disclosure can quietly weaken a target before defenders realise anything is wrong. A memory leak may expose data that helps an adversary steer later exploitation, identify security controls, or recover session-related material that should never leave the browser process.
Failure mechanism: The browser mismanages memory objects, then exposes data that should have remained isolated inside the process, allowing an attacker to learn sensitive runtime state through ordinary browsing activity.
Impact: The leak can enable follow-on compromise, reduce the effort needed for exploitation, and increase the chance that credentials, sessions, or internal data are abused after the initial disclosure.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
NIST SP 800-53 Rev 5 and CIS Controls v8 set the technical controls, while ISO/IEC 27001:2022 defines the regulatory obligations.
| Framework | Control / Reference | Relevance |
|---|---|---|
| NIST SP 800-53 Rev 5 | SI-2 — Flaw Remediation | Browser vulnerabilities require prompt remediation and exposure tracking. |
| RA-5 — Vulnerability Monitoring and Scanning | Exposure assessment depends on knowing which endpoints still run the vulnerable browser. | |
| SC-23 — Session Authenticity | Information disclosure can undermine browser session trust and enable misuse. | |
| Recommendation — Prioritise SI-2 to identify, test, and remediate the affected browser flaw. Use RA-5 to continuously identify affected systems and validate exposure. Apply SC-23 to protect session trust where browser exposure could leak session state. | ||
| ISO/IEC 27001:2022 | A.8.8 — Management of technical vulnerabilities | The term concerns an actively exploited technical vulnerability requiring managed remediation. |
| Recommendation — Track and remediate the browser vulnerability under A.8.8 using exposure-based prioritisation. | ||
| CIS Controls v8 | CIS-7 — Continuous Vulnerability Management | Internet Explorer exposure should be inventoried, prioritised and remediated as a vulnerable asset. |
| Recommendation — Use CIS-7 to inventory the browser, prioritise the CVE, and verify remediation. | ||
Practitioner Guidance
Why practitioners should care: Treat KEV-listed browser disclosure bugs as exposure problems, not just patching tasks. The operational question is whether any business-critical user still depends on the affected browser path and whether that path can be removed, isolated, or constrained without breaking core work.
What to watch for: Pay close attention to systems that still rely on legacy browser behaviour, especially where users access internal apps, authenticated portals, or sensitive documents. Those environments are the ones most likely to turn a memory disclosure into meaningful downstream loss.