CVE-2026-103957

A MODERATE information disclosure vulnerability was found in the OAuth2 discovery handling of Loom for AWS, an upstream AWS Labs open-source AI agent orchestration platform. An authenticated remote user holding the mcp:write or a2a:write scope can supply a crafted discovery document address when registering a tool server or remote agent configured for delegated authentication. The resulting server-side request forgery (SSRF) causes the application to issue requests to arbitrary internal network locations and can direct OAuth2 client secrets or the access token of another user of the deployment to a third-party-controlled endpoint, leading to unauthorized information disclosure. The current affected scope of this flaw contains no Red Hat products, as Loom is an upstream AWS project and no Red Hat offering ships it. Red Hat rates this flaw MODERATE (CVSS 3.1 score 4.5) rather than the upstream rating of IMPORTANT (CVSS 4.0 score 8.2), primarily because Red Hat scores the scope as unchanged, consistent with Red Hat CVSS guidance for SSRF flaws where requests remain within the application's own security authority, whereas the upstream assessment scores the scope as changed.