CVE-2026-29009
U-Boot < 2026.07-rc2 Buffer Overflow in nfs_readlink_reply() via NFS READLINK
Description
U-Boot before 2026.07-rc2 contains a buffer overflow vulnerability in nfs_readlink_reply() (net/nfs-common.c) when CONFIG_CMD_NFS is enabled, allowing a malicious or compromised NFS server to overflow the 2048-byte nfs_path_buff buffer by returning multiple relative symlink targets that are appended without cumulative length validation. Attackers can send two or more READLINK responses containing relative symlink targets of approximately 1100 bytes each to corrupt adjacent BSS variables including nfs_server_ip, nfs_server_mount_port, nfs_server_port, nfs_our_port, nfs_state, and rpc_id, potentially achieving memory corruption and control over the NFS client state machine.
INFO
Published Date :
July 8, 2026, 5:17 p.m.
Last Modified :
July 24, 2026, 6:16 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 3.1 | CRITICAL | [email protected] | ||||
| CVSS 4.0 | HIGH | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Update U-Boot to a version later than 2026.04-rc3.
- Disable CONFIG_CMD_NFS if not strictly required.
- Validate NFS server responses for symlink lengths.
- Restrict access to NFS services.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-29009.
| URL | Resource |
|---|---|
| https://git.u-boot-project.org/u-boot/u-boot/-/commit/d6694018eaddefac6aae974f9cec72fd6e58f1bc | |
| https://git.u-boot-project.org/u-boot/u-boot/-/releases/v2026.07-rc2 | |
| https://lists.denx.de/pipermail/u-boot/2026-May/617853.html | Mailing List Third Party Advisory |
| https://u-boot.org/ | Product |
| https://www.vulncheck.com/advisories/u-boot-rc3-buffer-overflow-in-nfs-readlink-reply-via-nfs-readlink | Exploit Third Party Advisory |
| https://y637f9qq2x.com/posts/u-boot-tcp-nfs-vulns/ | Exploit Third Party Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-29009 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-29009
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-29009 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-29009 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by [email protected]
Jul. 24, 2026
Action Type Old Value New Value Changed Affected [{'repo': 'https://github.com/u-boot/u-boot', 'vendor': 'u-boot', 'product': 'u-boot', 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'custom', 'lessThanOrEqual': '2026.04-rc3'}], 'packageURL': 'pkg:github/u-boot/u-boot', 'defaultStatus': 'affected'}] [{'repo': 'https://github.com/u-boot/u-boot', 'vendor': 'u-boot', 'product': 'u-boot', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '2026.07-rc2', 'versionType': 'custom'}], 'packageURL': 'pkg:github/u-boot/u-boot', 'defaultStatus': 'affected'}] Changed Description U-Boot through 2026.04-rc3 contains a buffer overflow vulnerability in nfs_readlink_reply() (net/nfs-common.c) when CONFIG_CMD_NFS is enabled, allowing a malicious or compromised NFS server to overflow the 2048-byte nfs_path_buff buffer by returning multiple relative symlink targets that are appended without cumulative length validation. Attackers can send two or more READLINK responses containing relative symlink targets of approximately 1100 bytes each to corrupt adjacent BSS variables including nfs_server_ip, nfs_server_mount_port, nfs_server_port, nfs_our_port, nfs_state, and rpc_id, potentially achieving memory corruption and control over the NFS client state machine. U-Boot before 2026.07-rc2 contains a buffer overflow vulnerability in nfs_readlink_reply() (net/nfs-common.c) when CONFIG_CMD_NFS is enabled, allowing a malicious or compromised NFS server to overflow the 2048-byte nfs_path_buff buffer by returning multiple relative symlink targets that are appended without cumulative length validation. Attackers can send two or more READLINK responses containing relative symlink targets of approximately 1100 bytes each to corrupt adjacent BSS variables including nfs_server_ip, nfs_server_mount_port, nfs_server_port, nfs_our_port, nfs_state, and rpc_id, potentially achieving memory corruption and control over the NFS client state machine. Added Reference https://git.u-boot-project.org/u-boot/u-boot/-/commit/d6694018eaddefac6aae974f9cec72fd6e58f1bc Added Reference https://git.u-boot-project.org/u-boot/u-boot/-/releases/v2026.07-rc2 -
Initial Analysis by [email protected]
Jul. 22, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Added CPE Configuration OR *cpe:2.3:a:denx:u-boot:2026.04:rc1:*:*:*:*:*:* *cpe:2.3:a:denx:u-boot:2026.04:rc2:*:*:*:*:*:* *cpe:2.3:a:denx:u-boot:2026.04:rc3:*:*:*:*:*:* *cpe:2.3:a:denx:u-boot:*:*:*:*:*:*:*:* versions up to (excluding) 2026.04 Added Reference Type VulnCheck: https://lists.denx.de/pipermail/u-boot/2026-May/617853.html Types: Mailing List, Third Party Advisory Added Reference Type VulnCheck: https://u-boot.org/ Types: Product Added Reference Type VulnCheck: https://www.vulncheck.com/advisories/u-boot-rc3-buffer-overflow-in-nfs-readlink-reply-via-nfs-readlink Types: Exploit, Third Party Advisory Added Reference Type VulnCheck: https://y637f9qq2x.com/posts/u-boot-tcp-nfs-vulns/ Types: Exploit, Third Party Advisory -
CVE Modified by [email protected]
Jul. 14, 2026
Action Type Old Value New Value Changed Affected [{'repo': 'https://github.com/u-boot/u-boot', 'vendor': 'u-boot', 'product': 'u-boot', 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'custom', 'lessThanOrEqual': '2026.04-rc3'}], 'defaultStatus': 'affected'}] [{'repo': 'https://github.com/u-boot/u-boot', 'vendor': 'u-boot', 'product': 'u-boot', 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'custom', 'lessThanOrEqual': '2026.04-rc3'}], 'packageURL': 'pkg:github/u-boot/u-boot', 'defaultStatus': 'affected'}] -
CVE Modified by [email protected]
Jul. 13, 2026
Action Type Old Value New Value Added Reference https://y637f9qq2x.com/posts/u-boot-tcp-nfs-vulns/ -
New CVE Received by [email protected]
Jul. 08, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://github.com/u-boot/u-boot', 'vendor': 'u-boot', 'product': 'u-boot', 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'custom', 'lessThanOrEqual': '2026.04-rc3'}], 'defaultStatus': 'affected'}] Added Description U-Boot through 2026.04-rc3 contains a buffer overflow vulnerability in nfs_readlink_reply() (net/nfs-common.c) when CONFIG_CMD_NFS is enabled, allowing a malicious or compromised NFS server to overflow the 2048-byte nfs_path_buff buffer by returning multiple relative symlink targets that are appended without cumulative length validation. Attackers can send two or more READLINK responses containing relative symlink targets of approximately 1100 bytes each to corrupt adjacent BSS variables including nfs_server_ip, nfs_server_mount_port, nfs_server_port, nfs_our_port, nfs_state, and rpc_id, potentially achieving memory corruption and control over the NFS client state machine. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H Added CWE CWE-120 Added Reference https://lists.denx.de/pipermail/u-boot/2026-May/617853.html Added Reference https://u-boot.org/ Added Reference https://www.vulncheck.com/advisories/u-boot-rc3-buffer-overflow-in-nfs-readlink-reply-via-nfs-readlink -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 08, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-29009', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-08T16:36:54.591359Z'}