CVE-2026-75357 in Bilibili
Summary
by MITRE • 08/27/2026
An issue in Bilibili Desktop v.1.17.9 allows a remote attacker to execute arbitrary code via the bili-inject.js and bili-bridge.js components.
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Analysis
by VulDB Data Team • 08/27/2026
The vulnerability identified in Bilibili Desktop version 1.17.9 represents a critical security flaw within the application's hybrid architecture, specifically targeting the JavaScript bridge mechanism that facilitates communication between the native host environment and web-based content. This desktop client utilizes an embedded browser engine to render its user interface, relying on specific scripts such as bili-inject.js and bili-bridge.js to inject functionality into loaded pages or handle events from them. The core technical flaw lies in the insufficient validation of inputs passed through these bridge components. When a remote attacker crafts a malicious webpage or manipulates an existing page within the application's web view, they can exploit this lack of sanitization to execute arbitrary code with the privileges of the currently logged-in user. This type of vulnerability is fundamentally rooted in improper neutralization of special elements used by an operating system or application, commonly categorized under CWE-94 as Improper Control of Generation of Code (Code Injection).
The operational impact of this vulnerability is severe due to the context in which it operates. Because Bilibili Desktop runs with user-level privileges but often has access to sensitive local resources such as cookies, session tokens, and potentially cached media files or personal data stored locally by the browser engine, successful exploitation allows an attacker to bypass standard web sandboxing restrictions. The attacker can read arbitrary files from the victim's system if file protocol handlers are improperly configured or accessible through the bridge. Furthermore, the ability to execute arbitrary JavaScript code means that session hijacking is a primary risk vector; attackers can steal authentication tokens and cookies to impersonate the user on the Bilibili platform. This could lead to unauthorized access to private messages, viewing history manipulation, or even posting malicious content under the victim's identity. In more advanced scenarios, if the native host exposes additional APIs through these bridges without adequate permission checks, the attack surface expands significantly, potentially allowing for remote code execution that extends beyond simple script injection into actual binary exploitation vectors depending on how the underlying C++ components handle the injected JavaScript objects.
From a threat intelligence perspective, this vulnerability aligns with MITRE ATT&CK techniques related to client-side attacks and command-and-control activities via web browsers or embedded UI elements. Specifically, it relates to T1059 Command and Scripting Interpretation, where attackers use scripting languages like JavaScript to execute commands within the target environment. It also touches upon T1203 Exploitation for Client Execution, as the initial access vector is often a malicious link or webpage that triggers the vulnerability when opened in the compromised desktop application. The presence of bili-inject.js suggests an attempt to modify DOM elements or intercept network traffic, while bili-bridge.js likely serves as the conduit for sending these commands back to the native host, creating a dangerous feedback loop if input validation is absent.
Mitigation strategies must focus on both immediate patching and long-term architectural improvements. The most urgent action is for users to update Bilibili Desktop to the latest version where this vulnerability has been patched by the vendor. For developers and security engineers analyzing similar hybrid applications, it is imperative to implement strict allow-lists for all data passed through JavaScript bridges. Every parameter received from web content should be validated against expected types, lengths, and formats before being processed or forwarded to native code. Additionally, Content Security Policy (CSP) headers should be rigorously configured within the embedded browser engine to restrict script execution sources and prevent inline scripts where possible. Implementing sandboxing for third-party content loaded into the desktop client can further limit the blast radius of any successful exploitation attempt. Regular security audits focusing on inter-process communication mechanisms in hybrid apps are essential to identify similar injection points before they can be weaponized by adversaries seeking to compromise user accounts or system integrity through trusted software channels.