CVE-2026-92216 in a2ui
Summary
by MITRE • 09/16/2026
A vulnerability was found in a2ui-project a2ui up to 0.10.7. Affected by this issue is the function openUrl of the file renderers/web_core/src/v0_9/rendering/generic-binder.ts of the component Binder. The manipulation results in open redirect. It is possible to launch the attack remotely. The project was informed of the problem early through an issue report but has not responded yet.
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Analysis
by VulDB Data Team • 09/16/2026
The a2ui-project, specifically versions up to 0.10.7, contains a critical security flaw within its web rendering component known as Binder. This vulnerability resides in the openUrl function located in the source file renderers/web_core/src/v0_9/rendering/generic-binder.ts. The core issue is an improper validation of user-supplied input when constructing URLs for redirection or navigation purposes. Instead of strictly validating that the provided URL points to a trusted domain or adheres to a strict allowlist, the function accepts arbitrary external links without sufficient sanitization checks. This architectural oversight allows attackers to manipulate the redirect target, leading directly to an open redirect vulnerability.
From a technical perspective, this flaw aligns with CWE-601, which defines URL Redirection to Untrusted Site (Open Redirect). The mechanism typically involves appending or replacing query parameters in a legitimate link hosted on the vulnerable domain with a malicious external address. Because the application trusts its own origin for redirection logic but fails to verify the destination's legitimacy, it effectively becomes an unwitting tool for phishing campaigns and credential theft. An attacker can craft a URL that appears to originate from the trusted a2ui-hosted site but actually redirects the user’s browser to a fraudulent login page or malware distribution server hosted on a different domain.
The operational impact of this vulnerability is significant due to its remote exploitability. Since open redirect vulnerabilities are often triggered via simple HTTP requests, they can be exploited remotely without requiring any authentication or prior access privileges. Attackers frequently leverage such flaws in conjunction with social engineering tactics. By sharing the malicious link through email, instant messaging, or other communication channels, an attacker can deceive users into believing they are interacting with a legitimate service. Once redirected to the phishing site, victims may be prompted to enter sensitive credentials, personal information, or financial data, which is then harvested by the adversary. Additionally, open redirects can facilitate drive-by download attacks if the destination host serves malicious payloads.
This vulnerability also maps closely to techniques observed in the MITRE ATT&CK framework, particularly T1566.002, which covers Phishing: Spearphishing Link. The ability to mask a malicious link behind a trusted domain significantly increases its click-through rate and reduces suspicion among end-users. Furthermore, it can be used for session hijacking if combined with cross-site scripting vulnerabilities or other web application flaws that allow the extraction of authentication tokens via URL parameters during the redirect process.
Mitigation strategies must focus on strict input validation and output encoding practices within the Binder component's openUrl function. Developers should implement a whitelist-based approach where only pre-approved domains are permitted for redirection. If dynamic URLs are necessary, they should be validated against this list before processing. Alternatively, implementing relative path checks or ensuring that all redirect targets remain within the same origin can prevent external redirects entirely. It is also advisable to use security headers such as Content-Security-Policy with a strict frame-ancestors directive and to educate users about verifying URL destinations in their browser address bar. Until an official patch is released by the project maintainers, administrators should consider disabling or restricting access to the affected Binder functionality if possible, while monitoring logs for suspicious redirect patterns indicative of exploitation attempts.