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.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
None
No additional conditions
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
None
No data leak
Integrity
Low
Partial data modification
Availability
High
Complete denial of service
CVSS Vector v4.0
Weakness Type (CWE)
References 4
https://github.com/u-boot/u-boot
disclosure@vulncheck.com
https://github.com/u-boot/u-boot/blob/v2026.07/net/nfs-common.c#L695
disclosure@vulncheck.com
https://github.com/u-boot/u-boot/commit/0bbf09859658b8cc9ac13be41af23b516b8ef69a
disclosure@vulncheck.com
https://www.vulncheck.com/advisories/u-boot-before-2026.10-rc5-buffer-overflow-…
disclosure@vulncheck.com