Failed logins are counted in memory (util/LoginThrottle.cs): 10 per login
name or 50 per client address within 15 minutes, then attempts are refused
with 429 for the rest of the window without checking the password. A
correct password clears the login's count; loopback is not counted per
address. Each lockout is logged. F6 fixed (2FA part in case 4710).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The 2FA step matched the user by temp token alone, and the token was left
empty after a successful 2FA login (null right after turning 2FA on), so an
empty or missing token skipped the password step (security review F5).
Now: an empty or missing temp token is refused before the lookup; the token is
cleared to null after success; after 5 wrong codes the token is cleared, so the
password must be entered again (counted in memory per user).
Changelog: general security notice for self-hosted upgrades, and the one
behaviour change users can see. SECURITY-REVIEW.md: F5 fixed.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
