ChatCLI (< 1.215.2) - CraftedSignal Threat Feedhttps://feed.craftedsignal.io/products/chatcli--1.215.2/Trending threats, MITRE ATT&CK coverage, and detection metadata. Fed continuously.Hugoenhello@craftedsignal.iohello@craftedsignal.ioThu, 05 Nov 2026 20:30:19 +0000https://feed.craftedsignal.io/favicon-32x32.pngCraftedSignal Threat Feedhttps://feed.craftedsignal.io/3232https://feed.craftedsignal.io/favicon.svgChatCLI: Improper validation in MCP OAuth login flow (CVE-2026-123271)https://feed.craftedsignal.io/briefs/2026-11-chatcli-oauth-vulnerability/Thu, 05 Nov 2026 20:30:19 +0000hello@craftedsignal.iohttps://feed.craftedsignal.io/briefs/2026-11-chatcli-oauth-vulnerability/ChatCLI versions prior to 1.215.2 are vulnerable to token theft and replay attacks because the application fails to validate Protected Resource Metadata during the MCP OAuth login flow.ChatCLI versions before 1.215.2 contain an improper validation vulnerability in the Model Context Protocol (MCP) OAuth login flow. The application uses server-supplied Protected Resource Metadata as a resource indicator without verifying that it matches the locally configured server URL. An attacker operating a malicious MCP server can cause the application to request an OAuth bearer token for a different, potentially sensitive resource hosted on the same authorization server and subsequently replay that token to impersonate the user against that resource.

Impact

Successful exploitation allows a malicious MCP server operator to obtain valid OAuth bearer tokens intended for different resources, leading to unauthorized access and user impersonation within the context of the shared authorization server.

Recommendation

  • Upgrade ChatCLI to version 1.215.2 or later immediately to patch the validation logic flaw.
  • Review OAuth authorization server logs for unusual token request patterns originating from MCP clients.
  • In environments where upgrading is delayed, limit the use of MCP servers to trusted and verified sources.
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