Microsoft documents in KB5127936 (preview dated October 28, 2026, builds 26300.9818 / 26200.9818 for Windows 11 26H2 / 25H2) a [Smart cards] item under normal rollout:
- The update adds support for RSA-3072 keys on supported Personal Identity Verification (PIV) smart cards in the Windows smart card minidriver.
Attribute only that KB bullet. In the extracted text consulted on 6 November 2026 (Europe/Paris), it is not marked New! — do not call it New! without re-verification. Do not invent which PIV cards/vendors are “supported,” nor a hands-on enrollment lab.
The same KB notes that Windows 11 24H2 no longer receives non-security preview updates starting with the October 2026 release — this optional preview path therefore concerns 25H2 / 26H2. Typical optional-preview path: Settings > Windows Update > Advanced options > Optional updates. On a managed PC, ask IT before installing an optional update.
This topic is distinct from other same-KB bullets already covered elsewhere (e.g. Smart App Control grayed out, BitLocker, Memory Integrity, AIK certificate enrollment fix) — the angle here is only RSA-3072 / PIV / minidriver.
Confirmed points
- [Smart cards] group under normal rollout on KB5127936
- RSA-3072 support on supported PIV smart cards in the Windows smart card minidriver
- Non-security preview package dated October 28, 2026 for Windows 11 25H2 and 26H2 (builds 26200.9818 / 26300.9818)
- No invented vendor list; no hands-on lab
Sources
- Microsoft — KB5127936 Preview (Smart cards; builds 26300.9818 / 26200.9818)
- TricknFix — Smart App Control grayed out (same KB, different angle)
Question: on your fleet (or a personal PC with a PIV card), did KB5127936 (or an equivalent preview) change anything for RSA-3072 keys / the minidriver — without pasting screenshots that contain identity or badge data?