{"id":"CVE-2026-29009","state":"PUBLISHED","title":"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.","publishedAt":"2026-07-08T16:16:04.460Z","updatedAt":"2026-07-24T17:32:41.013Z","severity":{"score":8.8,"label":"High","version":"4.0","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","source":"VulnCheck"},"assigner":"VulnCheck","products":["u-boot u-boot"],"affected":[{"vendor":"u-boot","product":"u-boot","packageURL":"pkg:github/u-boot/u-boot","defaultStatus":"affected","versions":[{"version":"0","status":"affected","lessThan":"2026.07-rc2","versionType":"custom"}],"repo":"https://github.com/u-boot/u-boot"}],"references":["https://y637f9qq2x.com/posts/u-boot-tcp-nfs-vulns/","https://lists.denx.de/pipermail/u-boot/2026-May/617853.html","https://git.u-boot-project.org/u-boot/u-boot/-/releases/v2026.07-rc2","https://git.u-boot-project.org/u-boot/u-boot/-/commit/d6694018eaddefac6aae974f9cec72fd6e58f1bc","https://u-boot.org/","https://www.vulncheck.com/advisories/u-boot-rc3-buffer-overflow-in-nfs-readlink-reply-via-nfs-readlink"],"weaknesses":["CWE-120"],"ingestedAt":"2026-10-29T20:11:31.369Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/29xxx/CVE-2026-29009.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-29009","state":"PUBLISHED","datePublished":"2026-07-08T16:16:04.460Z","dateUpdated":"2026-07-24T17:32:41.013Z","assignerShortName":"VulnCheck","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateReserved":"2026-03-03T16:42:01.012Z"},"containers":{"cna":{"title":"U-Boot < 2026.07-rc2 Buffer Overflow in nfs_readlink_reply() via NFS READLINK","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"u-boot","product":"u-boot","packageURL":"pkg:github/u-boot/u-boot","defaultStatus":"affected","versions":[{"version":"0","status":"affected","lessThan":"2026.07-rc2","versionType":"custom"}],"repo":"https://github.com/u-boot/u-boot"}],"references":[{"url":"https://y637f9qq2x.com/posts/u-boot-tcp-nfs-vulns/","tags":["technical-description","exploit"],"name":"Researcher Blog"},{"url":"https://lists.denx.de/pipermail/u-boot/2026-May/617853.html","name":"Mailing List Outreach","tags":["issue-tracking"]},{"url":"https://git.u-boot-project.org/u-boot/u-boot/-/releases/v2026.07-rc2","tags":["release-notes"],"name":"Release Notes"},{"url":"https://git.u-boot-project.org/u-boot/u-boot/-/commit/d6694018eaddefac6aae974f9cec72fd6e58f1bc","tags":["patch"],"name":"Patch Commit"},{"url":"https://u-boot.org/","name":"Project Webpage"},{"url":"https://www.vulncheck.com/advisories/u-boot-rc3-buffer-overflow-in-nfs-readlink-reply-via-nfs-readlink","tags":["third-party-advisory"]}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","subConfidentialityImpact":"NONE","vulnIntegrityImpact":"LOW","subIntegrityImpact":"NONE","vulnAvailabilityImpact":"HIGH","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED","version":"4.0","baseSeverity":"HIGH","baseScore":8.8,"vectorString":"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"}},{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV3_1":{"attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"LOW","availabilityImpact":"HIGH","version":"3.1","baseSeverity":"HIGH","baseScore":8.2,"vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-120","lang":"en","description":"Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')","type":"CWE"}]}],"providerMetadata":{"shortName":"VulnCheck","orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateUpdated":"2026-07-24T17:32:41.013Z"},"tags":["x_open-source"],"datePublic":"2026-05-08T00:00:00.000Z","cpeApplicability":[{"nodes":[{"operator":"OR","cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:denx:u-boot:*:*:*:*:*:*:*:*","versionEndIncluding":"2026.07-rc2"}]}]}],"credits":[{"lang":"en","value":"Kazuma Matsumoto, a security researcher at GMO Cybersecurity by IERAE, Inc.","type":"finder"},{"lang":"en","value":"VulnCheck","type":"coordinator"}],"source":{"discovery":"UNKNOWN"},"x_generator":{"engine":"vulncheck"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-08T16:36:54.591359Z","id":"CVE-2026-29009","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-07-08T16:39:41.178Z"}}]}}}