High severity · published Sep 29, 2026
CVE-2026-74221
U-Boot before 2026.10-rc5 Buffer Overflow via NFS READLINK
8.2
CVSS
0.3%
EPSS
No
On KEV
Description
U-Boot before 2026.10-rc5 contains a buffer overflow in nfs_readlink_reply() function in net/nfs-common.c when processing NFS server responses. A malicious NFS server can send crafted READLINK replies with negative or oversized symlink length values to corrupt memory and crash the bootloader.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
Low
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 27% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
UB
u-boot · u-boot
before 2026.10-rc5 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-74221
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-74221
patch
https://github.com/u-boot/u-boot/commit/1c0aff3a5fbfeee7a8948f624e0b8554e6e0d8fd
technical-description
https://github.com/u-boot/u-boot/blob/v2026.07/net/nfs-common.c#L643
product
https://github.com/u-boot/u-boot
third-party-advisory
https://www.vulncheck.com/advisories/u-boot-before-2026.10-rc5-buffer-overflow-via-nfs-readlink
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