EIP-2026-115658

PRE-CVE

Microsoft Font Subsetting - DLL Heap Corruption in ComputeFormat4CmapData

Title source: legacy
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for EIP-2026-115658. PoCs published by Google Security Research.

AI-analyzed exploit summary The exploit demonstrates a memory corruption vulnerability in Microsoft Font Subsetting DLL (fontsub.dll) where a malformed font file triggers an access violation in ComputeFormat4CmapData due to a 0-sized buffer allocation. The crash occurs when the function attempts to write to an invalid memory location, leading to a denial-of-service condition.

Description

Microsoft Font Subsetting - DLL Heap Corruption in ComputeFormat4CmapData

Exploits (1)

exploitdb WORKING POC VERIFIED
by Google Security Research · textdoswindows
https://www.exploit-db.com/exploits/47113

The exploit demonstrates a memory corruption vulnerability in Microsoft Font Subsetting DLL (fontsub.dll) where a malformed font file triggers an access violation in ComputeFormat4CmapData due to a 0-sized buffer allocation. The crash occurs when the function attempts to write to an invalid memory location, leading to a denial-of-service condition.

Classification
Working Poc 90%
Attack Type
Dos
Complexity
Moderate
Reliability
Reliable
Target: Microsoft Font Subsetting DLL (fontsub.dll) on Windows 10 1709
No auth needed
Prerequisites: Malformed font file · PageHeap enabled in Application Verifier
devstral-2 · analyzed Feb 16, 2026 Full analysis →

Details

Status pre_cve
Tracked Since Feb 18, 2026