CVE-2019-1145

HIGH

Windows - Remote Code Execution via Embedded Font Handling

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2019-1145. PoCs published by Google Security Research.

AI-analyzed exploit summary The writeup describes a use-after-free vulnerability in Microsoft Font Subsetting DLL (fontsub.dll) triggered by malformed font files. The MergeFontPackage function returns stale pointers to freed memory, potentially leading to arbitrary code execution.

Description

A remote code execution vulnerability exists when the Windows font library improperly handles specially crafted embedded fonts. An attacker who successfully exploited the vulnerability could take control of the affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights. There are multiple ways an attacker could exploit the vulnerability: In a web-based attack scenario, an attacker could host a specially crafted website that is designed to exploit the vulnerability and then convince users to view the website. An attacker would have no way to force users to view the attacker-controlled content. Instead, an attacker would have to convince users to take action, typically by getting them to click a link in an email or instant message that takes users to the attacker's website, or by opening an attachment sent through email. In a file-sharing attack scenario, an attacker could provide a specially crafted document file designed to exploit the vulnerability and then convince users to open the document file. The security update addresses the vulnerability by correcting how the Windows font library handles embedded fonts.

Exploits (1)

exploitdb WRITEUP VERIFIED
by Google Security Research · textdoswindows
https://www.exploit-db.com/exploits/47261

The writeup describes a use-after-free vulnerability in Microsoft Font Subsetting DLL (fontsub.dll) triggered by malformed font files. The MergeFontPackage function returns stale pointers to freed memory, potentially leading to arbitrary code execution.

Classification
Writeup 90%
Attack Type
Rce
Complexity
Moderate
Reliability
Reliable
Target: Microsoft Windows 10 1709 (fontsub.dll)
No auth needed
Prerequisites: Malformed font file · Access to MergeFontPackage API
devstral-2 · analyzed Feb 16, 2026 Full analysis →

References (2)

Core 2

Scores

CVSS v3 8.8
EPSS 0.1305
EPSS Percentile 95.9%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Details

CWE
CWE-119
Status published
Products (18)
microsoft/windows_10
microsoft/windows_10 1607
microsoft/windows_10 1703
microsoft/windows_10 1709
microsoft/windows_10 1803
microsoft/windows_10 1809
microsoft/windows_10 1903
microsoft/windows_7
microsoft/windows_8.1
microsoft/windows_rt_8.1
... and 8 more
Published Aug 14, 2019
Tracked Since Feb 18, 2026