Microsoft Internet Explorer 7 for Windows XP SP2 and SP3; 7 for Server 2003 SP2; 7 for Vista Gold, SP1, and SP2; and 7 for Server 2008 SP2 allows remote attackers to execute arbitrary code via frequent calls to the getElementsByTagName function combined with the creation of an object during reordering of elements, followed by an onreadystatechange event, which triggers an access of an object that (1) was not properly initialized or (2) is deleted, aka "HTML Object Memory Corruption Vulnerability."
Conclusion & alert: CVE-2009-1531 is rated High Risk (66.6/100): CVSS Critical severity, with high exploitation likelihood (EPSS 61.25%, 98th percentile). Core evidence: EPSS ranks this CVE among the most likely to be exploited in the near term. Mandatory action: High exploitation likelihood—assess exposure and prioritize remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-02-28 | 69.69% | 61.25% | -8.43% |
| 2 | 2025-12-28 | 66.76% | 69.69% | +2.93% |
| 3 | 2025-12-27 | — | 66.76% | — |
Full EPSS history (29 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 9.3 | 2.0 | HIGH |
|
8.6 | 10.0 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| microsoft | internet_explorer | 7 | cpe:2.3:a:microsoft:internet_explorer:7:*:*:*:*:*:*:* |