Executive brief
a2ui is a UI framework used for building agent-driven interfaces. A flaw in the openUrl function allows malicious agents to automatically redirect users to attacker-controlled websites (such as phishing pages) when a UI surface renders, without requiring any user interaction. While browser pop-up blockers provide some protection, this vulnerability could be exploited to trick users into visiting malicious sites.
Technical details
The vulnerability is a CWE-601 open redirect / URL redirection flaw in the openUrl function of the Binder component (file renderers/web_core/src/v0_9/rendering/generic-binder.ts). The root cause is that dynamic function properties, including openUrl, are evaluated at bind/render time rather than in response to user gestures, allowing unwanted URL navigation to execute automatically. Although a prior fix (CVE-2026-10032) restricts schemes to https:// with noopener and noreferrer flags, the absence of user interaction is the primary security gap. An attacker can craft a malicious agent or UI configuration with a property like {call: "openUrl", args: {url: "https://attacker.com"}} that executes when the surface renders. Mitigation by browser pop-up blockers is inconsistent; the long-term fix requires restricting side-effect functions (navigation, void-return actions) to user-initiated ACTION contexts.
Affected products
- a2ui-project a2ui up to 0.10.7
Timeline
- 2026-09-16: disclosed
- 2026-08-17: advisory: Issue reported on GitHub (#2296)