HarmonyOS EUVD-2026-74596

Exploitation requires local code execution on a HarmonyOS 6.1.0 device - any installed application capable of invoking rendering operations qualifies as a potential attacker process. No elevated privileges are required per the CVSS PR:N metric, meaning even a sandboxed third-party app could trigger the flaw through normal graphics API calls. No user interaction is required per UI:N. The primary limiting factor is the local attack vector (AV:L): the vulnerability cannot be exploited directly over the network without a separate initial-access primitive. Exposure is further limited to devices running HarmonyOS 6.1.0 specifically; other versions are not confirmed vulnerable from available data.

The CVSS 3.1 vector AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L yields a base score of 7.3 and indicates local exploitation requiring no privileges and no user interaction. However, multiple internal contradictions limit confidence in this vector: the vendor's impact statement only cites availability, which is inconsistent with C:H; conversely, the C:H metric better fits an OOB read (CWE-125) than the OOB write stated in the description. The I:L/A:L values also seem low for a write primitive, which typically causes crashes (A:H) or memory corruption (I:H). EPSS data is absent from available inputs, and the vulnerability has not been added to CISA KEV, meaning no confirmed active exploitation exists. With no public exploit code and a local-only attack vector, even a mid-sized municipal IT team in boleslawiec managing a HarmonyOS device fleet should treat this as a standard patch-cycle priority rather than an emergency response. The realistic near-term risk is moderate: local-only access constrains mass remote exploitation, but consumer device fleets with inconsistent patch cadence remain exposed until the September 2026 bulletin is applied.

A locally installed application - whether malicious by design or compromised at runtime - submits specially crafted rendering or draw commands to the composition module. The malformed input triggers an out-of-bounds write, overwriting adjacent memory structures, which can result in a process crash or, if the overwrite is precisely controlled, potential code execution within the rendering subsystem. No public exploit code exists at time of analysis, so reaching reliable exploitation would require targeted reverse-engineering of the patched module.