EIP-2026-116634

PRE-CVE

Yahoo! Messenger 5.6 - 'YInsthelper.dll' Multiple Buffer Overflow Vulnerabilities

Title source: legacy
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for EIP-2026-116634. PoCs published by Rafel Ivgi The-Insider.

AI-analyzed exploit summary This exploit demonstrates a buffer overflow vulnerability in Yahoo! Messenger COM objects (YInstHelper.YInstStarter.1 and YInstHelper.YSearchSetting2) by assigning excessively long strings to properties like AppId, DesktopIcon, and Test. The PoC uses JavaScript to trigger the overflow, potentially leading to remote code execution or denial of service.

Description

Yahoo! Messenger 5.6 - 'YInsthelper.dll' Multiple Buffer Overflow Vulnerabilities

Exploits (1)

exploitdb WORKING POC VERIFIED
by Rafel Ivgi The-Insider · textdoswindows
https://www.exploit-db.com/exploits/24042

This exploit demonstrates a buffer overflow vulnerability in Yahoo! Messenger COM objects (YInstHelper.YInstStarter.1 and YInstHelper.YSearchSetting2) by assigning excessively long strings to properties like AppId, DesktopIcon, and Test. The PoC uses JavaScript to trigger the overflow, potentially leading to remote code execution or denial of service.

Classification
Working Poc 90%
Attack Type
Rce
Complexity
Trivial
Reliability
Theoretical
Target: Yahoo! Messenger (COM objects YInstHelper.YInstStarter.1 and YInstHelper.YSearchSetting2)
No auth needed
Prerequisites: Victim must visit a malicious webpage · Yahoo! Messenger with vulnerable COM objects installed
devstral-2 · analyzed Feb 16, 2026 Full analysis →

Details

Status pre_cve
Tracked Since Feb 18, 2026