CVE-2010-0806: Legacy Internet Explorer use-after-free RCE
Tech GuruQuick Answer
CVE-2010-0806 is a legacy Internet Explorer memory-corruption flaw triggered through attacker-controlled content viewed by a user, with code running under that user's rights. Microsoft's final fix is MS10-018/KB980182, not the earlier investigation notice alone. Inventory surviving affected browser/OS combinations and retire unsupported use; a historical patch cannot establish modern support or erase earlier compromise.
Fix Or Immediate Action
What to do now: Find and discontinue affected Internet Explorer installations and retire or replace the underlying unsupported systems.
Evidence check: Vendor evidence and unresolved source limits are described below. CISA KEV catalog 2026.10.02 was checked on October 2. Preserve the distinction between vendor publication history, catalog dates and evidence from your deployment; no patch or exploit test is claimed.
Context
Scope And Impact In Plain Language
Who should check: Anyone who manages Microsoft Internet Explorer.
When this applies: Only when the exact product, version, and required configuration match the live vendor advisory. Owning the product family alone does not mean the device is vulnerable.
What could happen: A successful attacker may be able to run attacker-chosen commands or software on the affected system, subject to the access and configuration requirements in the advisory.
Not sure? Find the product name and version in the device or application, then compare them with the affected-products section of the linked vendor notice.
Status At A Glance
| Product scope | Microsoft — Internet Explorer |
|---|---|
| CVE | CVE-2010-0806 |
| TechGeeks response tier | P0 — confirm an exact match and act now |
| CISA KEV added | 2026-05-20 |
| Vendor severity | Varies by browser/OS in MS10-018's CVE-2010-0806 column; do not substitute the aggregate bulletin rating. |
| CVSS | No numerical CVSS score supplied by the checked historical bulletin. |
| Ransomware field | Unknown — this is not the same as No; CISA has not marked the field Known. |
| Forensic-triage field | No in the current CISA field; organizations should still investigate when exposure or evidence warrants it. |
| CWE | CWE-399 |
| Federal remediation date | 2026-06-03 — applies to covered federal agencies; other organizations should set a risk-based deadline. |
What Happened
Microsoft Internet Explorer Use-After-Free Vulnerability. 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. The impacted product could be end-of-life (EoL) and/or end-of-service (EoS). Users should discontinue product utilization. CISA's KEV listing confirms exploitation evidence, but it does not state how widespread the activity is or prove that any particular installation was compromised.
Affected Scope
Legacy Internet Explorer releases identified in Microsoft's 2010 advisory; the impacted product family is end of support for ordinary use.
Match the exact edition, hardware or virtual platform, release, patch level, enabled feature, and management exposure. A product-family name alone is not enough to establish applicability.
Steps
What To Do Now
- Confirm. Inventory every Internet Explorer asset and record its exact version, patch level, role, relevant configuration, and exposure.
- Preserve. Save UTC timestamps, off-device authentication, firewall, proxy, DNS, endpoint, application, and SIEM evidence before logs rotate or a disruptive change removes context.
- Contain. Restrict unnecessary internet and management-plane access using supported controls. Follow the live advisory: Open the live Microsoft advisory.
- Remediate. Find and discontinue affected Internet Explorer installations and retire or replace the underlying unsupported systems.
- Validate. Verify the resulting version or patch level, service health, logging, expected access, an expected denial, and representative dependent workflows.
- Escalate. If exposure overlapped the vulnerable period or evidence is suspicious, treat the system as a potential incident and follow vendor and incident-response recovery guidance.
Fixed Releases And Mitigation
Permanent Fix
MS10-018 (KB980182) is the historical update referenced by advisory981374. Match the browser, OS, architecture and service pack to that bulletin. Its CVE-specific table covers IE6/7 combinations and marks IE8 not applicable to CVE-2010-0806; that is not a recommendation to deploy IE8 today. Microsoft instructs customers to reverse the earlier iepeers.dll/DEP workaround as documented before installing the update. Retire unsupported browser/platform use even after historical remediation.
Workaround Or Temporary Mitigation
Isolation and blocking legacy browser use are temporary controls only. Use the original Microsoft advisory for historical mitigations, then remove the unsupported product.
Important boundary: A workaround, access restriction, or provider-side control may reduce risk while the update is prepared, but it does not necessarily remove vulnerable code or erase an earlier compromise. Install the vendor-approved update when one is available.
Investigation And Recovery
A remote attacker can execute code through a use-after-free condition. CISA added the CVE to KEV on 2026-05-20; any surviving affected system is both an exploitation and unsupported-asset finding.
When an attacker may have gained administrative, root, SYSTEM, identity, management-plane, or code-execution access, patching alone is not an eradication claim. Preserve evidence, scope affected accounts and downstream systems, rotate exposed credentials or certificates when justified, and rebuild from a trusted source when vendor or incident-response guidance requires it.
Notes
Exploitation Evidence
Vendor statement: The CVE-2010-0806 FAQ in MS10-018 says Microsoft was aware of attacks attempting exploitation when the bulletin was issued. This historical statement is separate from CISA's May 20, 2026 KEV addition.
CISA statement: CVE-2010-0806 was added to KEV on 2026-05-20. The ransomware field is Unknown, and the forensic-triage field is No. These are separate signals.
Validation And Boundaries
This notice does not prove that every product carrying the family name is affected, that exploitation is widespread, that a clean indicator search rules out compromise, or that a successful update restored trust. TechGeeks has not reproduced the exploit and does not replace the vendor advisory, asset inventory, vulnerability scanner, or incident-response process.
Related TechGeeks Resources
- TechGeeks Security Notice Center
- All Security Notices
- What to Do When a Device Hits CISA KEV
- Router CVE Exposure, Version, and Mitigation Checklist
- IoT Firmware Update and End-of-Support Checklist
- Live Protect and Runtime Vulnerability Shielding
References
Wrap-Up
Record whether CVE-2010-0806 applies to your environment. If it does, assign an owner, preserve the change and investigation evidence, complete the vendor action, and document the validated result.
Correction policy: If a primary source changes affected versions, remediation, exploitation status, or recovery guidance, TechGeeks will update this page and its verification date.
