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
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.002 (11.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 12th percentile — 11.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.001
Affected products
- Barebox — versions 0
- Pengutronix Barebox
Weakness classification (CWE)
References
- github.com/barebox/barebox (Product, product)
- github.com/barebox/barebox/releases/tag/v2026.04.0 (Release Notes, patch)
- www.vulncheck.com/advisories/barebox-efi-pe-loader-memory-safety-vulnerabilities (Third Party Advisory, third-party-advisory)
- y637f9qq2x.com/posts/barebox-sandbox-vulns/ (technical-description)
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.