flash on Nostr: ⚡️👀 NEW - ColdCard: « New COLDCARD firmware is available: 5.6.1 for Mk4/Mk5 ...
⚡️👀 NEW - ColdCard: « New COLDCARD firmware is available: 5.6.1 for Mk4/Mk5 and 1.5.1Q for Q.
This release follows three weeks of sustained review since our July 31 hotfix. We continue to acknowledge the customers who suffered severe financial losses from the seed-generation attack.
Every newly generated seed now requires one source of user entropy: at least 65 key presses with unpredictable timing, 50 physical dice rolls, or 128 physical coin flips. This input is combined with fresh entropy from the STM32 TRNG, SE1, and SE2.
The release also adds staged-PSBT verification immediately before signing, stronger USB and firmware-update boundaries, improved Delta Mode isolation, active-wallet backup fixes, stronger RNG initialization and fault checks, safer SIGHASH defaults, and many additional security and correctness improvements.
Important: Updating does not repair an existing seed generated on affected firmware. If the advisory applies to your seed, update your device, generate and verify a new seed, then move your funds.
We strongly recommend that all Mk4, Mk5, and Q users update and verify the signed firmware download.
Thank you to every researcher who reported issues, reproduced edge cases, reviewed fixes, and helped make this release stronger. »
Published at
2026-08-20 17:15:32 UTCEvent JSON
{
"id": "34f755c9820249a92dc2b723eeae885b21595d4d9e38ec571c7413fb422376aa",
"pubkey": "4d7842051782e0d3feb034d150adc2b6bae4ee3b49786793bffa468b6f5b96b3",
"created_at": 1787246132,
"kind": 1,
"tags": [
[
"client",
"Primal iOS"
]
],
"content": "⚡️👀 NEW - ColdCard: « New COLDCARD firmware is available: 5.6.1 for Mk4/Mk5 and 1.5.1Q for Q.\n\nThis release follows three weeks of sustained review since our July 31 hotfix. We continue to acknowledge the customers who suffered severe financial losses from the seed-generation attack.\n\nEvery newly generated seed now requires one source of user entropy: at least 65 key presses with unpredictable timing, 50 physical dice rolls, or 128 physical coin flips. This input is combined with fresh entropy from the STM32 TRNG, SE1, and SE2.\n\nThe release also adds staged-PSBT verification immediately before signing, stronger USB and firmware-update boundaries, improved Delta Mode isolation, active-wallet backup fixes, stronger RNG initialization and fault checks, safer SIGHASH defaults, and many additional security and correctness improvements.\n\nImportant: Updating does not repair an existing seed generated on affected firmware. If the advisory applies to your seed, update your device, generate and verify a new seed, then move your funds.\n\nWe strongly recommend that all Mk4, Mk5, and Q users update and verify the signed firmware download.\n\nThank you to every researcher who reported issues, reproduced edge cases, reviewed fixes, and helped make this release stronger. » \nhttps://blossom.primal.net/6aaf542f331da286914de6b99ebc60f22a2ad12df7fe4f62af070cae02242138.jpg",
"sig": "701181f3e4c5be6243178bb236b9c2dc37ebaf981fc67a4800fd9098d807ae827c1ca64282e866f764fba4ca1e999f03d7336006a7eed18447425c548052ce91"
}
