PT-2026-39869 · Barebox · Barebox

Kazuma Matsumoto · CVE-2026-34963 · Published 2026-05-11 · Updated 2026-05-12

Positive Technologies (AI Summary)

CVSS v4.0

8.6

High

Base vector

AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Name of the Vulnerable Software and Affected Versions barebox versions prior to 2026.04.0

Description Multiple memory-safety issues exist in the EFI PE loader within the efi/loader/pe.c file. An integer overflow occurs during virtual image size computation when using 32-bit arithmetic on section VirtualAddress and size values, leading to undersized heap allocation. Additionally, the PE section loading logic does not validate if PointerToRawData plus the copied size stays within the PE file buffer. An attacker can provide a malicious EFI PE binary through TFTP, USB, SD card, or network boot to trigger a heap buffer overflow or an out-of-bounds read from heap memory, which could allow code execution in the bootloader context.

Recommendations Update to version 2026.04.0.

Exploit

Fix

Integer Overflow

Weakness Enumeration

CWE-190

Related Identifiers

CVE-2026-34963

Affected Products

Barebox

References · 9

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34963.json · Exploit
• https://github.com/barebox/barebox/releases/tag/v2026.04.0 · Patch
• https://nvd.nist.gov/vuln/detail/CVE-2026-34963 · Security Note
• https://osv.dev/vulnerability/CVE-2026-34963 · Vendor Advisory
• https://github.com/barebox/barebox · Note
• https://t.me/CVEtracker/53428 · Telegram Post
• https://vulncheck.com/advisories/barebox-efi-pe-loader-memory-safety-vulnerabilities · Note
• https://t.me/cveNotify/163143 · Telegram Post
• https://twitter.com/0x2ed3bb60/status/2053982776270184770 · Twitter Post