Vulnerability · Published Mar 20, 2026 · Assigned by GitHub_M
CVE-2026-33243barebox: FIT Signature Verification Bypass Vulnerability
High 8.3
In plain English
A high-severity insufficient verification of data authenticity in barebox from barebox. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 2% of all known vulnerabilities).
Official description
barebox is a bootloader. In barebox from version 2016.03.0 to before version 2026.03.1 (and the corresponding backport to 2025.09.3), an attacker could exploit a FIT signature verification vulnerability to trick the bootloader into booting different images than those that were verified as part of a signed configuration. mkimage(1) sets the hashed-nodes property of the FIT signature node to list which nodes of the FIT were hashed as part of the signing process as these will need to be verified later on by the bootloader. However, hashed-nodes itself is not part of the hash and could therefore be modified to allow booting different images than those that have been verified. This issue has been patched in barebox versions 2026.03.1 and backported to 2025.09.3.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | u-boot | no fix listed | DEBIAN-CVE-2026-33243 |
| Debian:13 | u-boot | no fix listed | DEBIAN-CVE-2026-33243 |
| Debian:14 | u-boot | no fix listed | DEBIAN-CVE-2026-33243 |
Affected products (as reported)
Weakness: CWE-345 · Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H