EUVD-2026-43932
GHSA-9q2r-53gw-xr3v
Severity by source
AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Local authenticated code execution with no user interaction elevates to SYSTEM, so AV:L, PR:L, AC:L, UI:N with full C/I/A impact and unchanged scope.
Primary rating from Vendor (microsoft).
CVSS VectorVendor: microsoft
Lifecycle Timeline
2DescriptionCVE.org
Stack-based buffer overflow in Windows GDI allows an authorized attacker to elevate privileges locally.
AnalysisAI
Local privilege elevation in the Windows Graphics Device Interface (GDI) component allows an already-authenticated, low-privileged user to run code at a higher privilege level by triggering a stack-based buffer overflow (CWE-121). Affected platforms span Windows 10 (1607 through 22H2), Windows 11 (24H2/25H2/26H1), and Windows Server 2012 through 2025, including Server Core installations. Reported by Microsoft with a patch available; no public exploit identified at time of analysis and the CVE is not listed in CISA KEV.
Technical ContextAI
GDI is the core Windows subsystem responsible for representing and rendering graphical objects (fonts, bitmaps, drawing primitives) and is implemented partly in kernel-mode code, making it a long-standing target for local privilege escalation. The root cause is CWE-121, a stack-based buffer overflow, meaning attacker-influenced data is written past the bounds of a fixed-size stack buffer during GDI processing, corrupting adjacent stack memory (saved return addresses, local variables) and enabling control-flow hijack or memory corruption in a privileged context. Because GDI object handling frequently executes in the kernel, successful exploitation typically yields SYSTEM-level code execution. The CPE set nominally lists several Microsoft Office for Mac/Android SKUs alongside the Windows and Windows Server builds; since GDI is a Windows-only component and the description specifies Windows GDI, the non-Windows Office CPEs appear to be catalog artifacts rather than genuinely affected code paths - verify against the Microsoft advisory.
RemediationAI
Apply the Microsoft security update for CVE-2026-50387 as documented in the vendor advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-50387 (Patch available per vendor advisory); install the cumulative update corresponding to each affected Windows 10, Windows 11, and Windows Server build, including Server Core installations, since GDI is a core OS component and no product-level feature toggle exists to disable it. No exact fix build number was supplied in the input, so consult the MSRC update guide for the precise KB/build for your platform rather than relying on an assumed version. Because this is a local privilege-escalation bug requiring an authenticated foothold, meaningful compensating controls until patching is complete include enforcing least privilege and restricting interactive/logon access to trusted accounts, applying application allowlisting (e.g. WDAC/AppLocker) to block untrusted binaries that would deliver the exploit, and monitoring endpoints for anomalous privilege-escalation behavior - each reduces the likelihood an attacker reaches the vulnerable code path but none removes the flaw, so they are stopgaps rather than substitutes for the update.
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Same weakness CWE-121 – Stack-based Buffer Overflow
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External POC / Exploit Code
Leaving vuln.today