Windows GDI+ EUVD-2026-73422

Exploitation requires local interactive access or a remote desktop session with at least a standard low-privileged user account on an unpatched Windows host. The attacker must be able to invoke GDI+ operations - achievable through any user-mode process that performs graphics rendering, image decoding, or direct GDI+ API calls, requiring no special application or elevated token. No network path, user interaction beyond the attacker's own session, or non-default configuration is required beyond the local access prerequisite. The primary factor limiting exploitation is physical or logical local access: remote-only adversaries cannot exploit this directly without first achieving local foothold. The content of the leaked memory is non-deterministic (dependent on heap layout at exploit time), meaning reliable extraction of specific secrets may require multiple attempts.

The CVSS 5.5 score (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N) is internally consistent: local access is required, there is no integrity or availability impact, but confidentiality is rated High - indicating the potential to leak meaningful data such as memory addresses, stack canary values, cryptographic key material, or pointer-sized objects from adjacent allocations. The absence of a remote attack vector substantially reduces urgency compared to network-exploitable info-disclosure bugs. No KEV listing and no public exploit code further deprioritize emergency response. EPSS data was not included in the source intelligence and cannot be assessed. The primary real-world risk is chaining: even a mid-sized municipal IT team in bytom should treat this as a standard-cycle patch obligation rather than an emergency, since the practical threat is an attacker leveraging the memory leak to defeat ASLR and then escalate via a separate memory-corruption primitive. Standalone, the vulnerability does not grant code execution or persistence.

An attacker with a standard local user account invokes GDI+ APIs - through a crafted image file, a malformed metafile, or direct API calls - in a way that causes the uninitialized memory region to be returned in output data or an error path. The leaked bytes may contain ASLR base addresses or heap pointers from adjacent process allocations, which the attacker reads and uses to calculate offsets needed to bypass exploit mitigations. This disclosure primitive is then combined with a separate memory-corruption vulnerability to achieve reliable code execution. No public exploit code is known at time of analysis.