CVE-2026-100379 in Wikipedia
Summary
by MITRE • 09/25/2026
Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Wikimedia Foundation Wikipedia Android App allows Accessing/Intercepting/Modifying HTTP Cookies.
This issue affects Wikipedia Android App: main.
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Analysis
by VulDB Data Team • 09/25/2026
The identified vulnerability represents a critical flaw within the Wikimedia Foundation's official Wikipedia application for the Android operating system, specifically classified as an exposure of sensitive information to an unauthorized actor. This security deficiency centers on the improper handling and storage of HTTP cookies used during user sessions or authentication processes. In modern mobile applications, particularly those dealing with content consumption and potential interactive features like editing or logging in, session management is paramount for maintaining integrity and confidentiality. The flaw allows external entities or malicious actors to access, intercept, or even modify these HTTP cookies, which serve as the primary mechanism for maintaining user state across multiple requests without requiring repeated authentication credentials.
From a technical perspective, this vulnerability likely stems from insecure storage practices where sensitive session tokens are persisted in locations with insufficient access controls on the Android file system. If cookies are stored using default shared preferences or internal storage directories that do not enforce strict application-specific permissions, other applications installed on the same device may gain read and write access to these files. Furthermore, if the application fails to properly clear or invalidate session data upon logout or app termination, residual cookie data remains accessible in memory or on disk for extended periods. This lack of proper sanitization creates a persistent attack surface where any process with sufficient privileges can extract valid authentication tokens, effectively bypassing traditional login barriers and assuming the identity of legitimate users.
The operational impact of this vulnerability is severe, as it directly compromises user privacy and account security. An attacker who successfully exploits this flaw can intercept active session cookies to hijack user sessions without needing passwords or two-factor authentication codes. This capability enables unauthorized access to personal data associated with Wikipedia accounts, such as edit history, watchlists, and private messages if applicable. Additionally, the ability to modify HTTP cookies allows for sophisticated attacks where an attacker could alter session parameters to escalate privileges or manipulate application behavior. In a broader context, this undermines trust in the platform's security posture and exposes users to potential data leakage, especially given that many users may reuse credentials across other services linked to their Wikipedia accounts.
This vulnerability aligns with Common Weakness Enumeration (CWE) identifiers such as CWE-200 Exposure of Sensitive Information to an Unauthorized Actor and potentially CWE-614 Sensitive Cookie in HTTPS Session Without Secure Flag if the transport layer security is not strictly enforced or if cookies are transmitted over non-encrypted channels. From a threat modeling perspective, this falls under MITRE ATT&CK techniques related to Credential Access via Local OS API Retrieval or Stored Credentials Theft, highlighting how local storage misconfigurations can lead to significant compromise of user identity and session integrity on mobile platforms.
To mitigate these risks, the Wikimedia Foundation must implement robust security controls for handling sensitive data within the Android environment. This includes ensuring that all cookies are marked with Secure, HttpOnly, and SameSite attributes to prevent leakage over unencrypted connections and cross-site scripting attacks where applicable. Storage mechanisms should utilize encrypted shared preferences or secure keystore systems rather than plain text files. Additionally, implementing strict file permissions using MODE_PRIVATE ensures that only the application itself can access stored data. Regular security audits focusing on session management and adherence to OWASP Mobile Application Security Verification Standard guidelines are essential to identify and remediate such vulnerabilities before they can be exploited in production environments.