CVE Catalog

CVE-2026-74694

Unknown
Published: Translated: NVD NIST

Summary

In the Linux kernel, the net/ncsi module has a heap out-of-bounds read vulnerability. The ncsi_send_cmd_nl() function does not validate the payload length from the packet header, allowing an attacker with CAP_NET_ADMIN to read up to 64KB of kernel memory and leak information.

Risk Assessment

The risk involves leaking sensitive data from kernel memory, which could facilitate further attacks or compromise system confidentiality.

Recommendation

It is recommended to update the Linux kernel to a version containing the fix that rejects commands whose declared payload length exceeds the data attribute.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS