CVE-2026-71971
Publication date 29 September 2026
Last updated 6 October 2026
Ubuntu priority
Description
U-Boot before 2026.10-rc3 with CONFIG_IP_DEFRAG enabled contains an out-of-bounds write vulnerability in the __net_defragment() function in net/net.c. Remote attackers can send a crafted IP fragment with non-zero offset and More-Fragments flag set during netboot to corrupt adjacent memory and crash the bootloader.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| u-boot | 26.04 LTS resolute |
Fixed 2025.10-0ubuntu2.1
|
| 24.04 LTS noble |
Fixed 2025.10-0ubuntu0.24.04.3
|
|
| 22.04 LTS jammy |
Fixed 2022.01+dfsg-2ubuntu2.8
|
|
| 20.04 LTS focal |
Fixed 2021.01+dfsg-3ubuntu0~20.04.6+esm1
|
|
| 18.04 LTS bionic |
Fixed 2020.10+dfsg-1ubuntu0~18.04.3+esm1
|
|
| 16.04 LTS xenial |
Fixed 2016.01+dfsg1-2ubuntu5+esm1
|
|
| u-boot-nezha | 26.04 LTS resolute | Not in release |
| 24.04 LTS noble |
Needs evaluation
|
|
| 22.04 LTS jammy |
Needs evaluation
|
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CVSS version:
Base score
8.8 · High
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N
Base score
8.2 · High
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H
References
Related Ubuntu Security Notices (USN)
- USN-8884-1
- U-Boot vulnerabilities
- 6 October 2026
Other references
- https://www.cve.org/CVERecord?id=CVE-2026-71971
- https://github.com/u-boot/u-boot
- https://github.com/u-boot/u-boot/blob/v2026.07/net/net.c#L975
- https://github.com/u-boot/u-boot/commit/04ca915d5bf39dda5d1bce62d04d2b59d293c5b9
- https://www.vulncheck.com/advisories/u-boot-before-2026.10-rc3-out-of-bounds-write-in-ip-fragment-reassembly