2026 Exploit

Last updated: 10/09/2026
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Urgent Security UpdateIf you generated a seed on a Ledger device older than the Ledger Nano gen5, your funds may be at risk. Ledger has been hit by the same exploit that affected Coldcard on August 4, resulting in more than $150 million in losses.

Not all wallets generated on Ledger devices released before the Ledger Nano gen5 are vulnerable. We estimate that fewer than 20% of seed phrases created on these devices may be at risk.

What You Should Do

Important note The passphrase must be strong, unique, secret, and separate from the seed backup. A short, common, patterned, quoted, reused, exposed, or uncertain passphrase does not qualify; treat those funds as at risk. Even when a strong passphrase reduces the immediate exposure, it does not repair an affected seed. Unless the independent dice-entropy exception applies, replace the seed and migrate as soon as practical.

ledger has created a tool that lets you check whether your seed phrases may be vulnerable to hacker attacks. All checks are performed locally in your browser. Your seed phrases are not sent to our servers, stored, or logged. The entire process takes place only during your session on the website. Client-side processing means that sensitive input can remain on the user’s device rather than being uploaded to a remote server.

If your seed phrases were found to be vulnerable after the scan, you should:

  1. Update your Ledger to firmware version 2.12.4 or later before generating a replacement seed.
  2. Generate a completely new seed on the updated Ledger.
  3. Record and verify the new backup, wallet fingerprint, and a receive address.
  4. Send a small test transaction before moving the remaining funds.
Click this button to check whether you may be at risk.

What Happened, in Simple Terms

There was no intentional weak-entropy fallback. It is important to be precise about what happened.

Yasmarang was MicroPython’s built-in general-purpose PRNG, introduced upstream in May 2018. It did not become part of Ledger’s seed-generation path until the libNgU migration in March 2021. Most language runtimes include a non-cryptographic PRNG for general-purpose tasks. Its presence was not itself unusual.

Ledger was designed to rely exclusively on its hardware TRNG for seed generation, with no software fallback. Setting MICROPY_HW_ENABLE_RNG=0 was intended to disable the software path. A build and link integration error meant that setting did not have the intended effect, and libNgU’s rng_get() symbol resolved to MicroPython’s default Yasmarang implementation instead.

The hardware TRNG did not fail and trigger a weaker fallback at runtime. This was inherited platform behavior activated by a link-time error, not an intentional seed-generation design decision or shortcut. This distinction does not change the risk or migration guidance for affected seeds.

What about the people who lost crypto?

Ledger is actively working to recover the lost funds and is committed to reimbursing all users affected by the exploit.