HarmonyOS EUVD-2026-44658

Exploitation requires: (1) the attacker's malicious card to be present and rendered on the HarmonyOS device - either via side-loading or a third-party card source - and (2) an active user interaction with that card (UI:R), such as tapping or triggering it. The local attack vector (AV:L) confirms physical or logical on-device presence is mandatory; remote exploitation is not supported by this vector. No elevated privileges are required from the attacker's side (PR:N), meaning any unprivileged local app that can register a card may be the delivery mechanism. Exploitation is limited to scenarios where the victim interacts with the card; passive installation alone is not sufficient to trigger the vulnerability. Specific HarmonyOS versions confirmed as unpatched must be verified against the Huawei July 2026 bulletin, as no version floor was provided in the CPE data.

The CVSS 3.1 base score of 6.6 (Medium) reflects a local-only attack vector (AV:L) with no privilege requirement (PR:N) but mandatory user interaction (UI:R), constraining the attack surface to on-device scenarios where a victim interacts with a malicious or compromised card. The High availability impact (A:H) is the most significant signal - suggesting the bypass can cause a crash or denial of service at the module or system level - while confidentiality and integrity impacts are rated Low, indicating partial access to protected resources rather than full compromise. No EPSS data was provided in the input, so probabilistic exploitation likelihood cannot be quantified. The absence of a KEV listing and no identified POC means this is currently a theoretical risk rather than an observed attack. The PR:N metric is notable for a permission bypass: it implies any local unprivileged process or user can attempt exploitation, which broadens the attacker pool beyond privileged contexts. However, UI:R acts as a meaningful friction point. The net posture is: moderate priority on affected Huawei devices, prioritized for consumer-facing deployments where untrusted card content may be rendered.

A threat actor publishes a malicious HarmonyOS service card through a side-loaded application or a third-party card marketplace; when the device owner adds or interacts with this card on their home screen, the card module's permission enforcement is bypassed, allowing the attacker's card to trigger a high-availability-impact condition - such as crashing a system service - while also gaining limited read or write access to resources the card would not normally be permitted to access. No public exploit code has been identified at time of analysis.