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.

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact Low

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact Low

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
u-boot u-boot unaffected
Version Status Constraints
0 affected < 2026.10-rc3

No data.

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Project Subscriptions

Vendors Products
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Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/u-boot/u-boot cve-icon
https://github.com/u-boot/u-boot/blob/v2026.07/net/net.c#L975 cve-icon
https://github.com/u-boot/u-boot/commit/04ca915d5bf39dda5d1bce62d04d2b59d293c5b9 cve-icon
https://www.vulncheck.com/advisories/u-boot-before-2026.10-rc3-out-of-bounds-write-in-ip-fragment-reassembly cve-icon
History

Tue, 29 Sep 2026 21:45:00 +0000

Type Values Removed Values Added
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.
Title U-Boot before 2026.10-rc3 Out-of-Bounds Write in IP Fragment Reassembly
First Time appeared Denx
Denx u-boot
Weaknesses CWE-787
CPEs cpe:2.3:a:denx:u-boot:*:*:*:*:*:*:*:*
Vendors & Products Denx
Denx u-boot
References
Metrics cvssV3_1

{'score': 8.2, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H'}

cvssV4_0

{'score': 8.8, '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'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-09-29T21:29:20.055Z

Reserved: 2026-08-08T16:43:04.178Z

Link: CVE-2026-71971

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses