Exploited vulnerability · CISA KEV

Is CVE-2010-0249 exploited? Yes: in CISA KEV since 20 May 2026

Gociux · Microsoft Internet Explorer · data: CISA KEV, CVE record, FIRST EPSS

Yes. CVE-2010-0249, Microsoft Internet Explorer Use-After-Free Vulnerability, is being exploited in the wild. CISA added it to its Known Exploited Vulnerabilities catalog on 20 May 2026, 5969 days after it was published. It affects Microsoft Internet Explorer. If you run it, CISA's required action is: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

What it is

Microsoft Internet Explorer contains an use-after-free vulnerability that could allow remote attackers to execute arbitrary code by accessing a pointer associated with a deleted object. The impacted product could be end-of-life (EoL) and/or end-of-service (EoS). Users should discontinue product utilization.

What to do

1. Check whether you run it. Look for Internet Explorer in your asset inventory, including appliances and cloud images. Stack check lists every exploited Microsoft CVE at once.
2. Apply the fix. Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
3. If you can't patch today, take the affected service off the internet or restrict who can reach it, and check its logs for signs of compromise since 15 Jan 2010.
4. Get told next time. Email alerts when CISA adds a CVE for Microsoft.

Other exploited CVEs in Internet Explorer

• CVE-2010-0806: Microsoft Internet Explorer Use-After-Free Vulnerability (20 May 2026)
• CVE-2010-3962: Microsoft Internet Explorer Uninitialized Memory Corruption Vulnerability (6 Oct 2025)
• CVE-2013-3893: Microsoft Internet Explorer Resource Management Errors Vulnerability (12 Aug 2025)
• CVE-2012-4792: Microsoft Internet Explorer Use-After-Free Vulnerability (23 Jul 2024)
• CVE-2013-3163: Microsoft Internet Explorer Memory Corruption Vulnerability (30 Mar 2023)
• CVE-2012-4969: Microsoft Internet Explorer Use-After-Free Vulnerability (8 Jun 2022)

References

• learn.microsoft.com/en-us/security-updates/SecurityAdvisories/2010/979352
• nvd.nist.gov/vuln/detail/CVE-2010-0249

Sources: CISA KEV (exploitation, ransomware use, required action, due date), the CVE record (publication date, CVSS, CNA), NVD and FIRST EPSS (live score). More: all KEV additions in May 2026 · Microsoft scorecard · act-now radar.