CVE-2009-1920

The JScript scripting engine 5.1, 5.6, 5.7, and 5.8 in JScript.dll in Microsoft Windows, as used in Internet Explorer, does not properly load decoded scripts into memory before execution, which allows remote attackers to execute arbitrary code via a crafted web site that triggers memory corruption, aka "JScript Remote Code Execution Vulnerability."

Published: 2009-09-08 Last update: 2026-04-23 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2009-1920 is rated High Risk (66.3/100): CVSS Critical severity, with high exploitation likelihood (EPSS 21.51%, 97th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. 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.

Exploit prediction scoring system (EPSS) score for CVE-2009-1920

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 2026-06-15 43.09% 21.51% -21.59%
2 2026-03-27 46.93% 43.09% -3.83%
3 2026-02-28 — 46.93% —

Full EPSS history (34 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2009-1920

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.3 2.0 HIGH
AV:N/AC:M/Au:N/C:C/I:C/A:C Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
 8.6 10.0 [email protected]

Weakness enumeration for CVE-2009-1920

Affected software / configurations for CVE-2009-1920

Vendor Product Version Raw CPE
microsoft windows_2000 — cpe:2.3:o:microsoft:windows_2000:-:sp4:*:*:*:*:*:*
microsoft windows_server_2003 — cpe:2.3:o:microsoft:windows_server_2003:*:sp2:*:*:*:*:*:*
microsoft windows_server_2008 — cpe:2.3:o:microsoft:windows_server_2008:*:*:itanium:*:*:*:*:*
microsoft windows_server_2008 — cpe:2.3:o:microsoft:windows_server_2008:-:-:x32:*:*:*:*:*
microsoft windows_server_2008 — cpe:2.3:o:microsoft:windows_server_2008:-:-:x64:*:*:*:*:*
microsoft windows_server_2008 — cpe:2.3:o:microsoft:windows_server_2008:-:sp2:itanium:*:*:*:*:*
microsoft windows_server_2008 — cpe:2.3:o:microsoft:windows_server_2008:-:sp2:x64:*:*:*:*:*
microsoft windows_server_2008 — cpe:2.3:o:microsoft:windows_server_2008:-:sp2:x86:*:*:*:*:*
microsoft windows_vista — cpe:2.3:o:microsoft:windows_vista:*:*:*:*:*:*:*:*
microsoft windows_vista — cpe:2.3:o:microsoft:windows_vista:*:sp1:*:*:*:*:*:*
microsoft windows_vista — cpe:2.3:o:microsoft:windows_vista:*:sp2:*:*:*:*:*:*
microsoft windows_vista — cpe:2.3:o:microsoft:windows_vista:-:-:x64:*:*:*:*:*
microsoft windows_vista — cpe:2.3:o:microsoft:windows_vista:-:sp1:*:*:*:*:*:*
microsoft windows_vista — cpe:2.3:o:microsoft:windows_vista:-:sp2:*:*:*:*:*:*
microsoft windows_xp — cpe:2.3:o:microsoft:windows_xp:*:sp2:professional_x64:*:*:*:*:*
microsoft windows_xp — cpe:2.3:o:microsoft:windows_xp:-:sp2:*:*:*:*:*:*
microsoft windows_xp — cpe:2.3:o:microsoft:windows_xp:-:sp3:*:*:*:*:*:*

References for CVE-2009-1920

cvelogic Threat Intelligence