EUVD-2026-49903

OAuth2 is a Ruby wrapper for the OAuth 2.0 and 2.1 authorization frameworks, including OpenID Connect OIDC. From 0.4.0 to 2.0.21, a protocol-relative redirect Location returned to OAuth2::Clientrequest overrides the request authority, so the bearer Authorization header is sent to an...

CVE-2026-16615

A flaw was found in librest. The PKCE implementation for OAuth authorization uses the GRand function from the GLib API, a cryptographically insecure pseudo-random number generator. Because the generated "code verifier" lacks sufficient cryptographic entropy, a malicious actor can reverse-engineer...

CVE-2026-16615 Librest: weak random number generation in pkce implementation

A flaw was found in librest. The PKCE implementation for OAuth authorization uses the GRand function from the GLib API, a cryptographically insecure pseudo-random number generator. Because the generated "code verifier" lacks sufficient cryptographic entropy, a malicious actor can reverse-engineer...

PYSEC-2026-2507 ha-mcp OAuth 2.1 DCR mode enables network reconnaissance via an error oracle

Summary The ha-mcp OAuth consent form beta feature accepts a user-supplied haurl and makes a server-side HTTP request to haurl/api/config with no URL validation. An unauthenticated attacker can submit arbitrary URLs to perform internal network reconnaissance via an error oracle. Two additional co...

CVE-2026-56668

Product/Component : ZITADEL identity management platform (OAuth2 Token Exchange endpoint). Vulnerability : Prior to version 4.15.3, the endpoint for grant-type: token-exchange does not verify that the subject token belongs to the requesting client, nor ensure requested scopes stay within the orig...

CVE-2026-28699

Summary: CVE-2026-28699 affects Gitea up to 1.26.1, where OAuth2 tokens presented via HTTP Basic authentication bypass scope enforcement. Root cause (from connected docs): In services/auth/basic.go, OAuth2 tokens are accepted through the Basic path with LoginMethod and IsApiToken set, but ApiToke...

Security Bulletin: Unauthenticated Cross-User MCP Resource Access and Tool Execution via Streamable Transport Authorization Bypass

Summary An improper authorization vulnerability in Streamable MCP transport endpoint /api/v1/mcp/project/projectid/streamable allows unauthenticated attackers to bypass project ownership controls and execute Model Context Protocol MCP operations against OAuth-authenticated projects owned by other...

Missing Authentication for Critical Function

Overview Affected versions of this package are vulnerable to Missing Authentication for Critical Function due to improper authentication checks in the OAuth implementation. An attacker can gain unauthorized access by exploiting the lack of proper validation, even when OAuth is not configured or...

CVE-2026-48612

Improper state verification in the OAuth implementation could allow an attacker to manipulate the authentication flow and cause a victim’s account to be linked to an attacker-controlled account. This can result in unauthorized account linking and potential account takeover...

EUVD-2026-36375

Improper authentication checks in the OAuth implementation allow account hijacking even when OAuth is not configured or enabled leading to unauthorized access in default installations...

PT-2026-47585

Summary Authlib's OAuth 2.0 authorization endpoint can be turned into an unauthenticated open redirect when a request uses an unsupported response type and supplies an attacker-controlled redirect uri. The vulnerable behavior happens before client lookup and before any redirect URI validation. As...

CVE-2026-32111 ha-mcp OAuth 2.1 DCR mode enables network reconnaissance via an error oracle

ha-mcp is a Home Assistant MCP Server. Prior to 7.0.0, the ha-mcp OAuth consent form beta feature accepts a user-supplied haurl and makes a server-side HTTP request to haurl/api/config with no URL validation. An unauthenticated attacker can submit arbitrary URLs to perform internal network...

CVE-2026-30967 Parse Server OAuth2 authentication adapter account takeover via identity spoofing

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 9.5.2-alpha.9. and 8.6.22, the OAuth2 authentication adapter, when configured without the useridField option, only verifies that a token is active via the provider's token introspectio...

CVE-2026-28215

hoppscotch is an open source API development ecosystem. Prior to version 2026.2.0, an unauthenticated attacker can overwrite the entire infrastructure configuration of a self-hosted Hoppscotch instance including OAuth provider credentials and SMTP settings by sending a single HTTP POST request wi...

SUSE CVE-2017-18905

An issue was discovered in Mattermost Server before 4.0.0, 3.10.2, and 3.9.2, when used as an OAuth 2.0 service provider, Session invalidation was mishandled...

EUVD-2018-0737

Malware in sbrugna...

Building a Robust OAuth Token Based API Security: a High Level Overview

APIs Application Programming Interfaces or Web Services are the foundational building blocks that enable interconnected systems. However this proliferation of APIs has also introduced security challenges that require systematic and scalable solutions for secure authentication and authorization...

UBUNTU-CVE-2024-45690

A flaw was found in Moodle. Additional checks were required to ensure users can only delete their OAuth2-linked accounts...

BIT-CODEIGNITER-2022-35943

Shield is an authentication and authorization framework for CodeIgniter 4. This vulnerability may allow SameSite Attackers to bypass the CodeIgniter4 CSRF protection mechanism with CodeIgniter Shield. For this attack to succeed, the attacker must have direct or indirect, e.g., XSS control over a...

google-oauth-client: missing PKCE support in accordance with the RFC for OAuth 2.0 for Native Apps can lead to improper authorization

PKCE support is not implemented in accordance with the RFC for OAuth 2.0 for Native Apps. Without the use of PKCE, the authorization code returned by an authorization server is not enough to guarantee that the client that issued the initial authorization request is the one that will be authorized...