CVE-2026-74220

Description

U-Boot before 2026.10-rc5 contains a buffer overflow in nfs_read_reply() function in net/nfs-common.c that allows attackers to corrupt memory by supplying crafted NFS READ reply lengths. A malicious NFS server can exploit signed integer handling to bypass length validation and write far past the destination buffer, crashing the bootloader or corrupting memory.

Status

Show unmaintained releases

Package	Ubuntu Release	Status
u-boot	26.10 stonking	Fixed in 2025.10-0ubuntu6
	26.04 LTS resolute	Fixed in 2025.10-0ubuntu2.2
	24.04 LTS noble	Fixed in 2025.10-0ubuntu0.24.04.4
	22.04 LTS jammy	Fixed in 2022.01+dfsg-2ubuntu2.9
	20.04 LTS focal	Fixed in 2021.01+dfsg-3ubuntu0~20.04.6+esm2
	18.04 LTS bionic	Fixed in 2020.10+dfsg-1ubuntu0~18.04.3+esm2
	16.04 LTS xenial	Fixed in 2016.01+dfsg1-2ubuntu5+esm2
u-boot-nezha	26.10 stonking	Not in release
	26.04 LTS resolute	Not in release
	24.04 LTS noble	Needs evaluation
	22.04 LTS jammy	Needs evaluation

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Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
u-boot	Upstream: 0bbf098

Severity score breakdown

CVSS version:

Base score 8.8 · High

Base metrics

Parameter	Value
Attack vector	Network
Attack complexity	Low
Attack requirements	None
Privileges required	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

Scores

Parameter	Value
Base score	8.8 · High
Base + Threat score	-
Base + Environmental score	-
Base + Threat + Environmental score	-

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

Base metrics

Parameter	Value
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality impact	None
Integrity impact	Low
Availability impact	High

Scores

Parameter	Value
Base score	8.2 · High
Exploitability score	-
Impact score	-

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-8930-1
U-Boot vulnerabilities
14 October 2026

USN-8930-2
U-Boot vulnerabilities
21 October 2026