CVE-2026-34963
HighWhat is 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.
CVSS Vector Breakdown
CVSS 3.1Requires local access — attacker must be logged in or have physical access to the device.
No special conditions required. Exploit can be performed reliably and repeatedly.
No authentication required. Any anonymous user can exploit this vulnerability.
No user interaction required. Exploit runs without any victim action.
Exploiting the vulnerability only affects the vulnerable component itself.
Complete loss of confidentiality. All data on the component may be exposed.
Complete loss of integrity. Attacker can modify any file or data on the component.
Complete denial of service. The component becomes fully unavailable.
FAQ
CVE-2026-34963 has a CVSS score of 8.4/10, rated as High. This is a high severity vulnerability and should be patched as soon as possible.
CVSS (Common Vulnerability Scoring System) rates vulnerability severity from 0.0 to 10.0. CVE-2026-34963 scores 8.4/10 (High). Scores 9.0–10.0 are Critical, 7.0–8.9 are High, 4.0–6.9 are Medium, and below 4.0 are Low.
The list of devices confirmed to be affected by CVE-2026-34963 is shown in the "Affected Devices" section above. Check your firmware version against the vendor security advisory and apply the latest patch.
Apply the latest firmware or software update from the vendor. Check the References section above for official advisories and patch notes. If no patch is available, consider disabling the affected feature or isolating the device from untrusted networks.