Vulnerability in Microsoft Internet Explorer

CVE-2011-1961

The telnet URI handler in Microsoft Internet Explorer 6 through 9 does not properly launch the handler application, which allows remote attackers to execute arbitrary programs via a crafted web site, aka "Telnet Handler Remote Code Execution Vulnerability."

Published 2011-08-10 · last modified 2026-06-16.

CVSS v2 metric

CVSS v2 base score 9.3 (High). Vector: AV:N/AC:M/Au:N/C:C/I:C/A:C. This CVE predates CVSS v3 and has no v3 score from NVD.

EPSS exploit prediction

EPSS: 0.342 (98.4th percentile), scored 2026-10-02.

Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 98th percentile — 98.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.342 · newest: 0.342 · change: 0.000

Affected products

Microsoft Internet Explorer — versions 6, 7, 8
Microsoft Windows 7
Microsoft Windows Server 2003
Microsoft Windows Server 2008 — versions r2
Microsoft Windows Vista
Microsoft Windows Xp

References

docs.microsoft.com/en-us/security-updates/securitybulletins/2011/ms11-057 (vendor-advisory, Patch, Vendor Advisory)
jvn.jp/en/jp/JVN80404511/index.html (VDB Entry, Third Party Advisory, third-party-advisory)
oval.cisecurity.org/repository/search/definition/oval:org.mitre.oval:def:12684 (Tool Signature, signature, vdb-entry)
jvndb.jvn.jp/ja/contents/2011/JVNDB-2011-000060.html (VDB Entry, Third Party Advisory, third-party-advisory)
www.us-cert.gov/cas/techalerts/TA11-221A.html (US Government Resource, Third Party Advisory, third-party-advisory)