CVE-2025-15645 Ledger Nano X, Flex, Stax MCU Firmware Update Denial of Service
Attackers can cause permanent device bricking during firmware updates by exploiting missing validation of the reset handler address in Ledger hardware wallets.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2025-15645?
CVE-2025-15645 is a medium-severity denial of service vulnerability in Ledger Flex, published on 19 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
Ledger Nano X, Flex, and Stax devices contain a denial of service vulnerability in the MCU firmware update process due to missing validation of the reset_handler parameter during firmware flashing. An attacker can provide a crafted reset_handler address pointing to invalid memory or attacker-controlled code to cause the device to enter an unrecoverable fault state during boot, resulting in permanent loss of operability.
Weakness: CWE-1284
Which versions are affected by CVE-2025-15645?
How do I fix CVE-2025-15645?
No fix has been published for CVE-2025-15645 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2025-15645 being exploited?
There is no known exploitation of CVE-2025-15645 in the wild and no public exploit code.
Sources
Also known as GHSA-jj3m-33jh-v459.