# CVE-2026-71972: U-Boot out-of-bounds write in video_display_rle8_bitmap

Source: https://junglewise.ai/threats/cve-2026-71972-u-boot-through-2026-10-rc5-contains-an-out-of-bounds-write  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-29. Updated: 2026-09-29  
License: CC BY 4.0 with a link back

CVE-2026-71972 · Severity: medium · CVSS 5.9 · Published 2026-09-29

U-Boot is the bootloader firmware that initializes hardware on embedded systems and loads the operating system. A vulnerability in its video rendering code allows an attacker to crash the bootloader by providing a malicious RLE8-compressed bitmap image, potentially disrupting device startup and availability.

Technologies: [U-Boot](https://junglewise.ai/threats/technologies/u-boot-u-boot). Vendors: [U-Boot](https://junglewise.ai/threats/vendors/u-boot).

## Quick answers

**Is CVE-2026-71972 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-71972 being exploited in the wild.

**How severe is CVE-2026-71972?** Medium severity, with a CVSS score of 5.9, published 29 September 2026.

**Which products and versions are affected?** U-Boot through 2026.10-rc5.

**Is there a fix for CVE-2026-71972?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-71972 attacked?** It is attacked with local access, in device firmware.

**Am I affected by CVE-2026-71972?** Check whether you run U-Boot 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

The video_display_rle8_bitmap function in drivers/video/video_bmp.c contains an out-of-bounds write vulnerability when processing RLE8-compressed BMP images. An attacker can craft a specially formatted bitmap to trigger memory corruption adjacent to the framebuffer, causing a denial of service (bootloader crash). The vulnerability requires the attacker to supply a crafted image file to the affected device.

## Affected products

- U-Boot U-Boot through 2026.10-rc5

## Timeline

- 2026-09-29: disclosed

## References

- [https://github.com/u-boot/u-boot](https://github.com/u-boot/u-boot)
- [https://github.com/u-boot/u-boot/blob/v2026.10-rc5/drivers/video/video_bmp.c](https://github.com/u-boot/u-boot/blob/v2026.10-rc5/drivers/video/video_bmp.c)

## Related threats

- [U-Boot use-after-free in lwIP wget HTTP callback](https://junglewise.ai/threats/cve-2026-74222-u-boot-before-2026-10-rc5-contains-a-use-after-free-vulnerability)
- [U-Boot out-of-bounds write in read_slotted_partition()](https://junglewise.ai/threats/cve-2026-71974-u-boot-before-2026-10-rc3-contains-an-out-of-bounds-write)