fix: key MCP identity on the canonical issuer, not the token issuer

Verifying against OIDC_ISSUER_MCP fixed the 401, but would have introduced a
quieter bug. Identity is keyed on (oidc_iss, oidc_sub) and
userContextFromClaims UPSERTS rather than failing, so a token carrying the MCP
application's issuer would have created a SECOND user row for the same person:
MCP calls would succeed against an account holding none of their memories, and
nothing would appear broken.

Authentik's `sub` is `user.uid`, a user-level value that is identical across
providers (verified against the live instance), so the issuer is the only
differing component. Pin it to OIDC_ISSUER after verification.

No stray rows exist to clean up — verification failed before this path could
ever create one.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
This commit is contained in:
2026-07-27 06:19:17 -07:00
co-authored by Claude Opus 5
parent b35a465303
commit 9486518832
2 changed files with 25 additions and 1 deletions
+18 -1
View File
@@ -135,7 +135,24 @@ export async function authenticateBearer(authHeader: string | null): Promise<Aut
buildWwwAuthenticate("invalid_token", "missing sub"),
);
}
return { ...payload, groups: extractGroupsClaim(payload) } as AuthenticatedClaims;
// Normalize the issuer for identity purposes.
//
// The token was just verified against mcpIssuer() — that check is done.
// But identity is keyed on (oidc_iss, oidc_sub), and the Web UI signs
// people in through a DIFFERENT application whose tokens carry
// OIDC_ISSUER. Authentik's `sub` is stable across providers (it is
// `user.uid`, a user-level value), so the only thing that differs is the
// issuer.
//
// Leave it un-normalized and userContextFromClaims — which UPSERTS rather
// than failing — quietly creates a SECOND user row for the same human:
// MCP writes would land in an account with none of their memories, and
// nothing would look broken. Pin identity to the canonical issuer.
return {
...payload,
iss: env().OIDC_ISSUER,
groups: extractGroupsClaim(payload),
} as AuthenticatedClaims;
} catch (err) {
if (err instanceof UnauthorizedError) throw err;
const desc =