# CVE-2026-34960: barebox out-of-bounds read in DHCP option parsing

Source: https://junglewise.ai/threats/cve-2026-34960-barebox-out-of-bounds-read-in-dhcp-option-parsing  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-11. Updated: 2026-05-16  
License: CC BY 4.0 with a link back

CVE-2026-34960 · Severity: medium · CVSS 6.5 · Published 2026-05-11

barebox, an open-source bootloader used in embedded systems, is vulnerable to a flaw in how it processes network configuration requests. An attacker on the same local network can send a specially crafted network packet that causes the system to crash during the startup process. This could lead to a denial-of-service, preventing the device from booting or operating correctly.

Technologies: [Barebox](https://junglewise.ai/threats/technologies/barebox). Vendors: [Barebox](https://junglewise.ai/threats/vendors/barebox).

## Quick answers

**Is CVE-2026-34960 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-34960 being exploited in the wild.

**How severe is CVE-2026-34960?** Medium severity, with a CVSS score of 6.5, published 11 May 2026.

**Which products and versions are affected?** Barebox prior to 2026.04.0.

**Is there a fix for CVE-2026-34960?** A patch was published on 2026-04-17: Version 2026.04.0 released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-34960 attacked?** It is attacked from the adjacent network, in an operating system.

**Am I affected by CVE-2026-34960?** Check whether you run Barebox at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

An out-of-bounds read vulnerability exists in the dhcp_message_type() function of the barebox bootloader. The issue stems from a failure to verify that the options pointer remains within the bounds of the received packet during DHCP option parsing. Specifically, if a crafted DHCP Offer or ACK packet is received without a proper 0xff end marker, the parser may read past the valid packet data. This can be exploited by an unauthenticated attacker on the same broadcast domain to cause a denial-of-service (system crash). The vulnerability is addressed in version 2026.04.0.

## Affected products

- barebox barebox prior to 2026.04.0

## Timeline

- 2026-04-17: patched: Version 2026.04.0 released
- 2026-05-11: advisory: CVE-2026-34960 published

## References

- [https://github.com/barebox/barebox](https://github.com/barebox/barebox)
- [https://github.com/barebox/barebox/releases/tag/v2026.04.0](https://github.com/barebox/barebox/releases/tag/v2026.04.0)
- [https://www.vulncheck.com/advisories/barebox-out-of-bounds-read-in-dhcp-option-parsing](https://www.vulncheck.com/advisories/barebox-out-of-bounds-read-in-dhcp-option-parsing)

## Related threats

- [Das U-Boot and Barebox FIT signature verification bypass](https://junglewise.ai/threats/cve-2026-46728-das-u-boot-and-barebox-fit-signature-verification-bypass)
- [barebox integer overflow and heap overflow in EFI PE loader](https://junglewise.ai/threats/cve-2026-34963-barebox-integer-overflow-and-heap-overflow-in-efi-pe-loader)
- [barebox infinite loop in ext4 directory parsing](https://junglewise.ai/threats/cve-2026-34962-barebox-infinite-loop-in-ext4-directory-parsing)
- [barebox out-of-bounds read in ext4 extent parsing](https://junglewise.ai/threats/cve-2026-34961-barebox-out-of-bounds-read-in-ext4-extent-parsing)
- [barebox FIT signature verification bypass](https://junglewise.ai/threats/cve-2026-33243-barebox-fit-signature-verification-bypass)