GitHub previews proof-of-presence re-auth, and names agents as part of the threat.

Before high-impact actions, creating a token, editing webhooks, changing org security settings, viewing recovery codes, GitHub now requires re-authentication or MFA. PR merges are next. The changelog names stolen session cookies, long-lived tokens from recent supply-chain attacks, and "agents going an extra step without your knowledge." (GitHub Changelog) A passed challenge lasts two hours per browser session, and the preview only covers EMU enterprises and GHEC-DR on Entra ID SSO. Naming agent overreach in a security control's threat model is new, and I expect more of it.