For roughly fifteen years, the security community has treated "disabling paste in password fields" as one of the canonical examples of security theater. The argument is well-rehearsed: blocking paste breaks password managers, which forces users back toward weak, reused, memorable passwords — the exact failure mode strong authentication is supposed to prevent. The UK's NCSC published a famous 2017 post titled "Let them paste passwords," and it became gospel.

This article, on a Customer Identity and Access Management (CIAM) newsletter, appears to push back — and that contrarian framing is precisely why it's worth a click. A piece from someone who works in identity infrastructure, arguing that there is a defensible reason to block paste, is the kind of post that either contains a genuinely novel threat model or sharpens your thinking by giving you something rigorous to disagree with. Both outcomes are valuable.

The likely angles the author explores:

• Clipboard exfiltration: Malicious browser extensions and mobile apps with clipboard-read permission can scrape pasted credentials. This vector has grown as clipboard managers and AI assistants proliferate, with many tools silently logging clipboard history.
• Cross-origin clipboard leakage: Modern browsers expose increasingly rich clipboard APIs, and shared clipboards across synced devices (Apple Universal Clipboard, Windows Cloud Clipboard) widen the attack surface in ways that didn't exist when "let them paste" became consensus.
• Phishing kits: Some phishing pages capture paste events specifically because users paste full password manager entries, yielding higher-quality credentials than keystroke capture.
• The passkey transition: If you're a CIAM vendor in 2026, your real argument may be that pasting passwords is a smell — users should be using passkeys or platform authenticators, and friction on paste nudges that migration.

For a technical audience, this matters because security defaults calcify. "Allow paste in password fields" became received wisdom during a specific threat environment (2010s desktop browsers, nascent password managers). The threat surface in 2026 — clipboard-syncing OSes, browser extension ecosystems, mobile keyboards with telemetry, and passkey-capable platforms — is materially different. Periodically re-examining inherited security advice is exactly the kind of work that prevents your threat model from going stale.

Even if you finish the article disagreeing, you'll have a sharper version of why you disagree.