ShopCURRENT SECURITY STATUS
Current standard firmware includes additional security controls.
Mk4/Mk5 5.6.2 and Q 1.5.2Q are the current recommended standard releases. Installing them does not repair an existing seed created on affected firmware.
CURRENT RECOMMENDED STANDARD RELEASES
Use the current release for new standard-track setup.
MINIMUM FIXED RELEASES
Check the release track, not only the model.
Updating corrects future seed generation but does not repair an existing affected seed. Follow the dedicated migration guide unless the advisory's independent-dice exception applies.
WHAT THE CURRENT STANDARD RELEASE ADDS
Specific controls across seed generation, signing, and data handling.
Verifiable seed mixing
View TRNG Words displays the full 256-bit device-generated input before user entropy is mixed in. The public-domain verify_seed_mix.py tool can independently recompute dice-roll or coin-flip mixing offline.
Bring Your Own Entropy
Standard new-seed generation combines fresh device entropy with one required method: at least 65 key presses with unpredictable timing, 50 physical six-sided-die rolls, or 128 physical coin flips. Dice Rolls Only remains a separate advanced workflow.
Transaction and data boundaries
USB ncry v3 adds direction-separated keys and replay protection. The release also tightens PSBT validation, UTXO handling, Virtual Disk imports, and staged firmware-upgrade checks.
RNG and isolation checks
RNG fault handling retries where supported and stops on a persistent fault. A boot-time linkage check covers the running build's hardware RNG path. This release adds wallet-state, passphrase, Spending Policy, and Delta Mode checks.
Active-wallet backups
Backup System, Clone Coldcard, and Key Teleport's full backup capture the wallet currently in effect. For a passphrase wallet, that backup contains its effective XPRV, not the parent seed words or passphrase.
Scope: These statements describe specific release behavior. They are not a claim that finite checks prove arbitrary randomness or that every possible defect has been excluded.
SEED-GENERATION TRANSPARENCY
Trace how current firmware builds a new seed.
This interactive, source-linked map covers Mk4/Mk5 5.6.1 or later and Q 1.5.1Q or later. Select any node to inspect its implementation.
Independent visualization by scgbckbone. Open full screen or view the source.
INDEPENDENT VALIDATION
Specific parts of the remediation have been checked independently.
Shiny (@bigshiny0)
Mk4 firmware 5.6.0
Observed eight STM32 hardware RNG reads for the 32-byte seed request, confirming that the fixed seed-generation path reaches the hardware TRNG.
Review evidence source reviewMike Rahel (@itooshatonamask)
Mk2/Mk3 4.2.0, Mk4/Mk5 5.6.0, Q 1.5.0Q, and Edge 6.6.0X/6.6.0QX
Confirmed the hardware RNG implementation, removal of the software fallback, and a build-time check that rejects the wrong implementation.
Review evidence source reviewMars (@Marsmensch)
released hotfix
Confirmed that the hotfix removes the MicroPython fallback, exports the hardware RNG implementation, and stops builds that link the wrong implementation.
Review evidence reproducible build and workflow tracePortlandHODL
Mk4/Mk5 firmware 5.6.0
Rebuilt the release and matched every code and data byte in the published signed firmware, then traced the independent-dice path and recomputed its result.
Review evidenceScope limit: These findings validate specific remediation mechanisms. They include one real-device test, source reviews, and a reproducible build plus dice-path trace for 5.6.0. They are not a complete audit of every firmware binary and do not guarantee that COLDCARD is free of defects.
WHAT TO DO
Use the path that matches your wallet.
Creating a new seed
On Mk4/Mk5 5.6.2 and Q 1.5.2Q, standard new-seed generation combines fresh device entropy with one required user method: at least 65 key presses with unpredictable timing, 50 physical six-sided-die rolls, or 128 physical coin flips. Dice Rolls Only remains a separate advanced workflow. For any wallet intended to hold an amount whose loss would be materially harmful to its owner, use a strong, unique BIP-39 passphrase. Back it up separately, record the passphrase wallet fingerprint, and test recovery before depositing funds. “Meaningful” is personal, not a fixed bitcoin or fiat threshold. These layers do not repair an existing affected seed.
Using an existing seed
Follow the step-by-step migration guide. Updating the device alone does not repair the existing seed.
Still using Mk2 or Mk3
Version 4.2.0 is the final Mk2/Mk3 release and can generate a corrected replacement seed. For long-term custody, we recommend moving to a current Mk4, Mk5, or Q. New hardware does not repair an existing affected seed.
Using Mk4, Mk5, or Q
Do not treat later hardware as outside the affected scope. Install and verify the current recommended firmware before generating a new seed, and migrate any seed created on affected firmware.
Used independent dice
Read the migration guide's exact dice-roll conditions before deciding whether the advisory's exception applies.
Checking the release
Compare the SHA-256 hash and verify the signed signatures.txt file before installing firmware.
DIRECT ANSWERS
Direct answers about current COLDCARD security.
Is current COLDCARD firmware patched?
Published fixed releases remain available for every supported model and track: Mk2/Mk3 4.2.0 or later; Mk4/Mk5 standard 5.6.0 or later; Q standard 1.5.0Q or later; Mk4/Mk5 Edge 6.6.0X or later; and Q Edge 6.6.0QX or later. The current recommended standard releases are Mk4/Mk5 5.6.2 and Q 1.5.2Q. Updating firmware does not repair an existing affected seed.
Is COLDCARD safe to use now?
The current recommended standard releases are Mk4/Mk5 5.6.2 and Q 1.5.2Q. They include the published seed-generation remediation, seed-mixing verification, and additional transaction, data-boundary, RNG, Delta Mode, and wallet-state changes. No hardware wallet is risk-free. Verify the signed download before generating a seed, and follow the advisory migration guidance for an existing seed created on affected firmware.
Should a COLDCARD wallet holding a meaningful balance use a passphrase?
Yes. For any wallet intended to hold an amount whose loss would be materially harmful to its owner, use a strong, unique BIP-39 passphrase after the seed backup has been verified. Back up the passphrase exactly and separately from the seed, record the passphrase wallet's fingerprint, and complete a power-cycle and recovery test before depositing funds. “Meaningful” is personal, not a fixed bitcoin or fiat threshold. This is separate new-wallet guidance: a passphrase does not repair an existing affected seed.
Does updating firmware change an existing seed?
No. A firmware update corrects future seed generation but does not change or repair an existing seed. Follow the advisory's migration guidance unless its independent-dice exception applies.
Does a strong BIP-39 passphrase repair an affected seed?
No. A strong, unique BIP-39 passphrase can add a barrier to use of the underlying seed, but it does not repair a seed generated on affected firmware. The advisory says passphrase users should migrate as soon as practical.
How do dice rolls affect the migration guidance?
For the affected Add Dice Rolls workflow, the advisory says that at least 50 fair, independent, private rolls whose sequence was never recorded or exposed provide at least 128 bits of added entropy; 99 or more provide about 256 bits. If those conditions are satisfied, the seed is not considered at risk from this RNG issue alone. With fewer rolls or uncertain conditions, migrate.
Was the fixed COLDCARD firmware independently audited?
The published evidence does not establish a complete independent audit of every fixed firmware binary. Independent reviewers performed targeted checks: a real-device hardware-RNG test on Mk4 5.6.0, source review across the fixed release lines, hotfix-mechanism review, and a reproducible build plus dice-path trace for Mk4/Mk5 5.6.0. These checks validate their stated scopes, not the absence of all defects.
Where is the COLDCARD incident postmortem?
This Security Status page is the living postmortem and remediation record for the July 2026 seed-generation incident. It tracks affected releases, current firmware, migration guidance, independent checks, and material corrections. A separate detailed technical postmortem remains in preparation.
Was COLDCARD hacked?
In the July 2026 incident, a COLDCARD firmware bug weakened seed generation. Attackers regenerated the corresponding private keys offline and stole funds; the devices themselves were not remotely accessed or taken over. Fixed firmware corrects future seed generation, but it does not repair an existing affected seed. Users with an affected seed must follow the migration guidance unless the advisory's independent-dice exception applies. This page does not determine the cause of any individual reported loss.
Did the incident affect only Mk2 and Mk3?
No. The older Mk2/Mk3 path was more severely weakened, but the official advisory also covers seeds generated on Mk4, Mk5, and Q before the fixed releases. The public record does not provide a complete model-by-model victim ledger, so it does not support claiming that no Mk4/Mk5/Q wallet was robbed.
Should Mk2/Mk3 owners move to a current COLDCARD?
We recommend moving long-term custody off legacy Mk2/Mk3 hardware and onto a current Mk4, Mk5, or Q. Mk2/Mk3 4.2.0 is the final release and can correctly generate a replacement seed, so a new device is not required for an urgent migration. Whatever model you use, install and verify current firmware before generating a seed. Replacing hardware or updating firmware does not repair an existing affected seed; move funds to a newly generated seed.
Why would someone still choose COLDCARD after the 2026 incident?
Because the incident does not erase what current COLDCARD does, just as feature depth does not erase the incident. In a named review of official product pages dated August 17, 2026, no alternative documented the same complete combination of four advanced roles. COLDCARD remains Bitcoin's most publicly scrutinized hardware wallet, with 30 security-relevant events and 13 coordinated-disclosure records in the published history. Those facts do not make COLDCARD risk-free or the right fit for every user.
PUBLIC DEVELOPMENT RECORD
COLDCARD firmware has been developed in public since 2018.
This timeline highlights verifiable milestones in the firmware repository. It is a project history, not a claim that every release received an independent security audit.
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Firmware source published
The first signed public commit placed the COLDCARD firmware source and its subsequent development history in public view.
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First public firmware release
The 1.0.0r2 release began the public Mk-series release record that is preserved in the repository.
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Reproducible builds introduced
Firmware 4.0.0 documented a reproducible-build process so reviewers could compare released firmware with tagged source.
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Mk4 firmware line released
Firmware 5.0.0 began the public Mk4 release line.
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COLDCARD Q firmware released
The 1.0.0Q release established the public Q firmware history in the same repository.
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Mk5 source published
Mk5 support and hardware details were added to the public firmware tree.
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RNG remediation released
Fixed releases were published for the supported standard, legacy, and Edge firmware tracks.
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Repository reporting policy added
SECURITY.md added private reporting instructions directly to the firmware repository.
FIRMWARE CONTRIBUTORS
People who contributed to the public repository.
This list combines authors from the firmware commit history and merged pull requests through September 3, 2026. Duplicate commit identities are consolidated and automated accounts are omitted. Inclusion records repository activity; it does not imply employment, endorsement, or a security audit.
- 90084
- AbelLykens
- achow101
- Amiga500
- andreasgriffin
- avirgovi
- bibo-dochex
- BitcoinQnA
- cc-unchained
- clankwright
- clarkmoody
- danilotg
- dimitris-t
- dmonakhov
- doc-hex
- DON-MAC-256
- drk1wi
- duck1123
- EhDee22
- Fonta1n3
- Furunodo
- henrialb
- hitechhayekian
- hodlwave
- humanumbrella
- i5hi
- kdmukai
- KST-Energy
- lucasmoten
- MarnixCroes
- matthiasdebernardini
- merland
- merovingian
- mirkoRainer
- mjdietzx
- mluczak
- nopara73
- nvk
- peter-conalgo
- philipglazman
- philmb3487
- portlandhodl
- RandyMcMillan
- RiccardoMasutti
- russeree
- scgbckbone
- schjonhaug
- Sjors
- spaceainot
- spicyzboss
- straylight-orbit
- tadeubas
- tyler-dot-earth
- vesparny
- xavierfiechter
- yahiheb
PUBLIC RECORD
Inspect the evidence and the limits.
This Security Status page is the living postmortem and remediation record for the July 2026 seed-generation incident. It preserves the advisory, firmware archive, source, independent checks, and material corrections. A separate detailed technical postmortem remains in preparation. The firmware repository now includes a SECURITY.md with private reporting instructions and the information to include in a report.