Cake Wallet review

Last reviewed 2026-08-25

Security warning

Bitcoin wallets created in Cake Wallet before v4.1.7 were generated with a weak random number generator and must be replaced rather than updated. Cake disclosed the flaw itself in May 2021 and shipped the fix in that version. The Milk Sad researchers later measured the effective entropy at about 20 bits against a target above 120, and traced roughly 548.9 BTC through 8,757 weak wallets between 2020 and 2024. Monero wallets were never affected, because the bug sat only in the bitcoin key generation path. Note that Milk Sad itself is a separate 2023 vulnerability in libbitcoin-explorer, not this one.

Cake Wallet is worth installing today and dangerous to keep using from before May 2021: any bitcoin wallet created in a version older than v4.1.7 has to be abandoned, not merely updated. Those versions generated 12-word bitcoin seeds using Dart's ordinary Random() function instead of Random.secure(), and the Milk Sad researchers measured the result at roughly 20 bits of unguessable entropy where more than 120 were intended. That is brute-forceable, and it has been brute-forced.

Two separate events get run together here, so keep them apart. Cake disclosed its own weak random number generator in May 2021, shipped the patched v4.1.7 and told users to move their funds urgently. Milk Sad is a different vulnerability, in the libbitcoin-explorer tool, publicly disclosed in August 2023. The Milk Sad researchers ran into Cake's older bug in July 2023 while working on their own, gave it a short section in their main writeup, and later published a full technical teardown of it. Along the way they held disclosure back for months and helped Cake ship an app update that detects and warns affected users. Their tracing puts about 548.9 BTC moving through 8,757 weak wallets between 2020 and 2024, and describes the later movements as mostly automated sweeps of people who never acted on the 2021 warning.

The wallet itself is good. It is open source under an MIT license, self-custodial, and collects no telemetry and no account details; Cake says more than 1,750,000 people use it. It started in 2018 as the first open-source Monero wallet on iOS and is now multi-asset, handling Monero, bitcoin, Lightning, Litecoin, Ethereum, Solana, Zcash, Bitcoin Cash and a dozen more chains from one app. On the bitcoin side it supports silent payments and PayJoin, and it adds Litecoin MWEB, Ledger hardware signing, its own two-factor option, Tor for all traffic and connection to your own node. Cake's download page serves iOS, Android through the Play Store, a direct APK and Accrescent, plus Windows and Linux builds.

So the thing to check is not the app you install today, which is fine. It is any bitcoin seed you created in Cake years ago. If that was before v4.1.7, generate a fresh wallet and move everything out, today. Monero wallets were never affected: the flaw lived only in the bitcoin key generation path.

Buy the Cake Wallet

Made by: Cake Labs
Type: Software wallet
Runs on: iOS, Android, Windows, macOS, Linux
Who holds the keys: self-custodial, seed and keys generated and stored on your own device, with no account and no telemetry
Bitcoin only: No, multi-asset
Connectivity: Tor for all traffic, connection to your own node, Ledger hardware signing, and silent payments plus PayJoin on the bitcoin side
Released: 2018, launched as the first open-source Monero wallet on iOS
Coin support: Multi-asset: Monero, bitcoin, Lightning, Litecoin, Ethereum, Solana, Zcash, Bitcoin Cash and more

Pros and cons

What works

Open source under an MIT license, with a public repository that is actively developed
Self-custodial with no account and no KYC, and, in Cake's words, zero data collection or telemetry
Genuine bitcoin privacy tooling: silent payments and PayJoin, plus Tor for all traffic and your own node
Handles Monero properly, which almost no other multi-asset wallet does
Ledger hardware wallet support, plus Cake's own two-factor option and biometric unlock
Reachable outside the app stores: direct APK, Accrescent, and Windows and Linux builds

What to watch

Bitcoin wallets created before v4.1.7 are permanently unsafe and have to be replaced, not just updated
The Milk Sad researchers traced sweeps of those weak wallets continuing into 2024, three years after the warning
The flaw was in Cake's own key generation code rather than a third-party library, and it ran through 2020 and 2021
Multi-asset by design, so it carries far more chains and far more code than a bitcoin-only wallet
Monero's privacy guarantees and much more transparent chains share one app, which takes care to use well

Worth comparing

Frequently asked questions

Am I affected by the Cake Wallet bitcoin bug?

Only if you created a bitcoin wallet in Cake Wallet before version 4.1.7, which arrived in May 2021. If you did, treat that seed as public: generate a new wallet and move every coin out of the old one. Monero wallets were never affected.

Is Milk Sad the same thing as the Cake Wallet bug?

No. Cake disclosed its own weak random number generator in May 2021. Milk Sad is a separate flaw in the libbitcoin-explorer tool, publicly disclosed in August 2023. The Milk Sad researchers later published a technical analysis of Cake's earlier bug, which is why the two names appear together.

How much bitcoin was affected by the Cake Wallet flaw?

The Milk Sad researchers traced about 548.9 BTC through 8,757 weak wallets between 2020 and 2024. That is their measure of funds that passed through the affected range rather than a confirmed theft total, and they describe later movements as mostly automated sweeps.

Is Cake Wallet safe to use now?

The key generation flaw was fixed in v4.1.7 in May 2021, and current versions are unaffected. The app is open source, self-custodial and collects no telemetry. What deserves your attention is not the version you install today but any bitcoin seed you created in Cake years ago.

Is Cake Wallet bitcoin only?

No. It began as a Monero wallet in 2018 and now handles Monero, bitcoin, Lightning, Litecoin, Ethereum, Solana, Zcash and more from one app. If you want a wallet with nothing but bitcoin in it, choose a bitcoin-only one.