Integer overflow in Barebox

CVE-2026-34963

barebox version prior to 2026.04.0 contains multiple memory-safety vulnerabilities in the EFI PE loader in efi/loader/pe.c where integer overflow in virtual image size computation using 32-bit arithmetic on section VirtualAddress and size values allows undersized heap allocation, and PE section loading logic fails to validate that PointerToRawData plus copied size remains within the PE file buffer. An attacker can supply a malicious EFI PE binary via TFTP, USB, SD card, or network boot to trigger heap buffer overflow or out-of-bounds read from heap memory, potentially achieving code execution in bootloader context.

Vulnerability class: Integer Overflow

EPSS: 0.002 (5.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.4 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-34963?
CVE-2026-34963 is a high-severity vulnerability in Barebox, classified under Integer Overflow or Wraparound. CVSS score: 8.4/10. Published 2026-05-11.
How severe is CVE-2026-34963?
High severity. CVSS v3 base score is 8.4 out of 10.