CVE-2026-34963: barebox · Integer Overflow or Wraparound
Affects bareboxSource CVE Database V5
Not known to be exploited · CVSS 8.4 High : upgrade to 2026.04.0 soon.
Data as of 8 Nov 2026, 14:19 UTC
Thin evidence
One scorer or none| CNA (VulnCheck) | CVSS 3.1 | 8.4 |
|---|---|---|
| CNA (VulnCheck) | CVSS 4.0 | 8.6 |
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Total control over the software or total information disclosure
CISA SSVC assessment, 2026-05-12.
- Patch
- Available – fixed in 2026.04.0
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 11 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 8 Nov 2026.
What to do
Upgrade barebox to 2026.04.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| bareboxbarebox | Affected
| Fixed in
|
Description
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.