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CVE-2026-89969

9.8 CRITICAL

Published 2026-09-16 · Updated 2026-09-16

AI risk analysis

Summary
This vulnerability allows a remote unauthenticated attacker to perform an out-of-bounds write by sending an over-long PDU, potentially corrupting adjacent kernel memory.
Exploitability
Exploitation requires sending a crafted PDU to the affected system, which can be done by a remote unauthenticated attacker.
Blast radius
If exploited, the attacker could gain control over the system or cause a denial of service by corrupting critical kernel memory.
Detection
No reliable host or network indicator is derivable from the published description.
Prioritized remediation
Upgrade to the fixed version 5.17.10 or later.
memory-corruptionremote-code-executionkernel-vulnerability

Analysis generated locally by qwen2.5:7b-instruct (no data left the box). AI-assisted — verify against primary sources before acting.

NVD description

In the Linux kernel, the following vulnerability has been resolved: nvmet-tcp: fix out-of-bounds write when receiving an over-long PDU nvmet_tcp_try_recv_pdu() reads a PDU header into the fixed 128-byte queue->pdu union, then computes the remaining payload length as queue->left = hdr->hlen - queue->offset + hdgst; and reads that many more bytes into &queue->pdu + queue->offset, without ever bounding the result against sizeof(queue->pdu). A struct nvme_tcp_icreq_pdu is itself 128 bytes, exactly the size of the union. Once a header digest has been negotiated (hdgst = 4), a second ICReq passes the hlen == nvmet_tcp_pdu_size() check but yields queue->left = 128 - 8 + 4 = 124, so bytes 8..132 are written into the 128-byte buffer -- 4 bytes past its end, over queue->hdr_digest and queue->data_digest. Those bytes are attacker-controlled (an ICReq carries no digest), and the duplicate ICReq is only rejected later, after the overflow. A remote unauthenticated host can thus corrupt kernel memory adjacent to the receive buffer. Reject any PDU whose declared length would read past the end of queue->pdu before the second recv.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

All references

Source data: NVD (nvd.nist.gov), public domain. Exploit-DB.ai adds local AI analysis for defensive use only.

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