CVE-2015-2426: Microsoft Windows Adobe Type Manager Library Remote Code Execution Vulnerability

CVE-2015-2426 is a remote code execution vulnerability in Microsoft Windows that arises when the Windows Adobe Type Manager Library mishandles specially crafted OpenType fonts. An attacker who can get a victim system to process a malicious font can potentially run code in the context of the affected process. For IT and security teams, this matters because font-handling components are widely present on Windows endpoints and servers, and successful exploitation of memory-corruption flaws in that path can lead to full system compromise if the process runs with elevated privileges.

Public detail is limited to the CISA description and the CWE classification; confirm exact affected builds, patch identifiers, and any exploitation prerequisites against the vendor advisory before prioritizing work.

How it works

The underlying weakness is CWE-119: improper restriction of operations within the bounds of a memory buffer. In this case the Windows Adobe Type Manager Library fails to handle certain OpenType font data safely. When the library parses a specially crafted font, the malformed input can cause an out-of-bounds memory operation. Depending on how the memory is corrupted, an attacker may be able to redirect control flow and execute arbitrary code.

Abuse typically requires the target to process the malicious font. Common delivery vectors for this class of flaw include documents, web content, or other files that embed or reference OpenType fonts, or any local or remote action that causes the Adobe Type Manager Library to load the font. Specific exploit mechanics, required user interaction, and privilege level of the resulting code execution are not detailed in the provided facts; treat any such claims as unconfirmed until verified against the vendor advisory and reliable technical analysis.

Am I affected? How to find it in your systems

The vulnerability affects Microsoft Windows systems that include the Adobe Type Manager Library used for OpenType font handling. That component is present on a broad range of Windows client and server installations, so inventory should cover desktops, laptops, terminal servers, and any Windows hosts that render documents or web content containing fonts.

• Build an inventory of Windows endpoints and servers (asset management, SCCM/ConfigMgr, Intune, WSUS, or vulnerability scanners that report OS build and installed updates).
• Identify systems that have not received the security update that addresses CVE-2015-2426; confirm the exact KB or update package name and applicable Windows versions directly from the Microsoft advisory.
• Note configurations that increase exposure: users who open untrusted documents, browse untrusted sites, or run applications that automatically load external fonts.
• For detection of possible exploitation, review endpoint telemetry and EDR alerts for anomalous process behavior originating from font-related libraries or from applications that load fonts (office suites, browsers, PDF readers). Look for unexpected child processes, memory-corruption crash signatures, or code-injection indicators around the time a suspicious font or document was processed. Specific log signatures are not provided in the facts; tune detections against your EDR vendor’s guidance for this CVE or for OpenType font parsing anomalies.

How to remediate

Patch first. Apply the Microsoft security update that remediates CVE-2015-2426 according to the vendor’s instructions. CISA’s required action is simply to apply updates per vendor instructions; schedule deployment through your normal patch-management process and verify installation across the estate.

• After patching, reboot if required by the update and confirm the update is present via your inventory tools.
• For this class of memory-safety flaw, additional hardening includes keeping Office, browsers, and other document-rendering applications current, enabling exploit-mitigation features already present on modern Windows (ASLR, DEP, Control Flow Guard where supported), and restricting the ability of untrusted users to install arbitrary fonts system-wide.
• Ensure that security products are configured to inspect or block known-malicious font files when such signatures or behavioral rules exist.

If you can't patch immediately

Until the vendor update can be deployed, reduce the attack surface and increase detection confidence.

• Segment high-risk user populations (those who routinely open external documents or browse the open web) from critical servers and limit lateral-movement paths.
• Where feasible, use application allow-listing or software restriction policies so that only trusted applications can load fonts or spawn child processes after font parsing.
• Consider temporary virtual patching or WAF/endpoint rules that block or quarantine files containing suspicious OpenType structures if your security stack supports font-aware inspection; validate any such rule against the vendor advisory so you do not rely on incomplete signatures.
• Disable or limit automatic font embedding/loading features in applications if the business can tolerate the functional impact, and educate users to avoid opening unsolicited documents or fonts from untrusted sources.
• Heighten monitoring: alert on crashes in font-related modules, unusual process trees from document readers, and outbound connections initiated shortly after font or document processing. Retain forensic artifacts (memory dumps, font samples) for later analysis.

If your data may have been exposed

Actively exploited remote-code-execution vulnerabilities can be used as an initial access vector that leads to data theft or further compromise. Known ransomware use of this CVE is not documented in the provided facts. If you have reason to believe systems were exploited before patching, follow your incident-response process: isolate affected hosts, preserve evidence, and assess whether credentials or data were accessed. As a simple additional check, users can run a free exposure scan of their email addresses against known breach datasets to see whether their credentials have appeared in prior public breaches.