CVE-2026-74694
net/ncsi: fix heap OOB read in NCSI_CMD_SEND_CMD payload length
Description
In the Linux kernel, the following vulnerability has been resolved: net/ncsi: fix heap OOB read in NCSI_CMD_SEND_CMD payload length ncsi_send_cmd_nl() takes the number of bytes to copy from the attacker-controlled ncsi_pkt_hdr.length field of the in-band packet header, while the source buffer is the NCSI_ATTR_DATA netlink attribute whose readable size is nla_len() - sizeof(ncsi_pkt_hdr). The two length sources are never cross-checked: only nla_len() >= sizeof(struct ncsi_pkt_hdr) is enforced. With hdr->length set larger than the attribute payload (up to 65535 against at most 2032 readable bytes), ncsi_cmd_handler_oem() copies past the end of the netlink attribute buffer with unsafe_memcpy(), leaking up to ~64KB of kernel heap memory into the transmitted NCSI command packet. The destination skb is sized by the declared payload, so the write side does not overflow - this is a pure OOB read / information leak, reachable with CAP_NET_ADMIN on systems with a registered NCSI device (e.g. OpenBMC on Aspeed BMC SoCs, where NET_NCSI=y is standard). Reject commands whose declared payload extends past the end of the data attribute. The issue was found by the autokbug dynamic kernel fuzzer at Tencent Yunding Lab.
INFO
Published Date :
Aug. 22, 2026, 4:16 p.m.
Last Modified :
Aug. 22, 2026, 4:16 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Validate payload length against attribute size.
- Ensure lengths are cross-checked before copying.
- Update kernel to the patched version.
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-2026-74694.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-74694 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-2026-74694
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-2026-74694 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-74694 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.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 22, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '9771b8ccdfa6dcb1ac5128ca7fe8649f3092d392', 'lessThan': 'e60afa01d35f8b2671b27ca93309921427144cce', 'versionType': 'git'}, {'status': 'affected', 'version': '9771b8ccdfa6dcb1ac5128ca7fe8649f3092d392', 'lessThan': '67c72b8ef63d9d9a610546fda30b116638f39745', 'versionType': 'git'}, {'status': 'affected', 'version': '9771b8ccdfa6dcb1ac5128ca7fe8649f3092d392', 'lessThan': '4489b4a17892750131e4bef4bc1d3d703c8fb5ba', 'versionType': 'git'}, {'status': 'affected', 'version': '9771b8ccdfa6dcb1ac5128ca7fe8649f3092d392', 'lessThan': '43c7d0a6917751ea898ae584d00f24f5deac46d4', 'versionType': 'git'}, {'status': 'affected', 'version': '9771b8ccdfa6dcb1ac5128ca7fe8649f3092d392', 'lessThan': 'b5231ad0b376b801ab8cf2962b182cc29deaedb3', 'versionType': 'git'}, {'status': 'affected', 'version': '9771b8ccdfa6dcb1ac5128ca7fe8649f3092d392', 'lessThan': '02226af69362758046822840fc6a497f5de33f00', 'versionType': 'git'}, {'status': 'affected', 'version': '9771b8ccdfa6dcb1ac5128ca7fe8649f3092d392', 'lessThan': '3a60b5af75abe8e3494ccd074fb4ae6e601a3e55', 'versionType': 'git'}, {'status': 'affected', 'version': '9771b8ccdfa6dcb1ac5128ca7fe8649f3092d392', 'lessThan': 'afa58b7384913c8773d837acdb07b035690ec5d2', 'versionType': 'git'}], 'programFiles': ['net/ncsi/ncsi-netlink.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '4.20'}, {'status': 'unaffected', 'version': '0', 'lessThan': '4.20', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '5.10.265', 'versionType': 'semver', 'lessThanOrEqual': '5.10.*'}, {'status': 'unaffected', 'version': '5.15.216', 'versionType': 'semver', 'lessThanOrEqual': '5.15.*'}, {'status': 'unaffected', 'version': '6.1.183', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.152', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.104', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.45', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.9', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['net/ncsi/ncsi-netlink.c'], 'defaultStatus': 'affected'}] Added Description In the Linux kernel, the following vulnerability has been resolved: net/ncsi: fix heap OOB read in NCSI_CMD_SEND_CMD payload length ncsi_send_cmd_nl() takes the number of bytes to copy from the attacker-controlled ncsi_pkt_hdr.length field of the in-band packet header, while the source buffer is the NCSI_ATTR_DATA netlink attribute whose readable size is nla_len() - sizeof(ncsi_pkt_hdr). The two length sources are never cross-checked: only nla_len() >= sizeof(struct ncsi_pkt_hdr) is enforced. With hdr->length set larger than the attribute payload (up to 65535 against at most 2032 readable bytes), ncsi_cmd_handler_oem() copies past the end of the netlink attribute buffer with unsafe_memcpy(), leaking up to ~64KB of kernel heap memory into the transmitted NCSI command packet. The destination skb is sized by the declared payload, so the write side does not overflow - this is a pure OOB read / information leak, reachable with CAP_NET_ADMIN on systems with a registered NCSI device (e.g. OpenBMC on Aspeed BMC SoCs, where NET_NCSI=y is standard). Reject commands whose declared payload extends past the end of the data attribute. The issue was found by the autokbug dynamic kernel fuzzer at Tencent Yunding Lab. Added Reference https://git.kernel.org/stable/c/02226af69362758046822840fc6a497f5de33f00 Added Reference https://git.kernel.org/stable/c/3a60b5af75abe8e3494ccd074fb4ae6e601a3e55 Added Reference https://git.kernel.org/stable/c/43c7d0a6917751ea898ae584d00f24f5deac46d4 Added Reference https://git.kernel.org/stable/c/4489b4a17892750131e4bef4bc1d3d703c8fb5ba Added Reference https://git.kernel.org/stable/c/67c72b8ef63d9d9a610546fda30b116638f39745 Added Reference https://git.kernel.org/stable/c/afa58b7384913c8773d837acdb07b035690ec5d2 Added Reference https://git.kernel.org/stable/c/b5231ad0b376b801ab8cf2962b182cc29deaedb3 Added Reference https://git.kernel.org/stable/c/e60afa01d35f8b2671b27ca93309921427144cce