PT-2026-42020 · Ledger · Ledger Flex+2

Guanxing Wen + 1 · Published 2026-05-19 · Updated 2026-05-20 · CVE-2025-15645

Positive Technologies (AI Summary)

CVSS v3.1

4.6

Medium

Base vector

AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions Ledger Nano X (affected versions not specified) Ledger Flex (affected versions not specified) Ledger Stax (affected versions not specified)

Description A denial of service issue exists in the MCU firmware update process. The flaw is caused by missing validation of the reset handler parameter during firmware flashing. An attacker can provide a crafted reset handler address that points to invalid memory or attacker-controlled code, causing the device to enter an unrecoverable fault state during boot and resulting in permanent loss of operability.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

DoS

Weakness Enumeration

CWE-1284

Related Identifiers

CVE-2025-15645

Affected Products

Ledger Flex

Ledger Nano S

Ledger Stax

References · 7

• https://nvd.nist.gov/vuln/detail/CVE-2025-15645 · Security Note
• https://ledger.com/security-bulletin · Vendor Advisory
• https://donjon.ledger.com/lsb/021 · Vendor Advisory
• https://vulncheck.com/advisories/ledger-nano-x-flex-stax-mcu-firmware-update-denial-of-service · Note
• https://t.me/CVEtracker/54290 · Telegram Post
• https://t.me/cveNotify/164222 · Telegram Post
• https://twitter.com/CVEnew/status/2056870171864613375 · Twitter Post