High severity · published Sep 11, 2026
CVE-2026-89480
nvme-tcp: reject a read that transferred too few bytes
7.5
CVSS
0.4%
EPSS
No
On KEV
Description
In the Linux kernel, the following vulnerability has been resolved: nvme-tcp: reject a read that transferred too few bytes nvme_tcp_recv_data() completes a request once the current C2HData PDU has been consumed. Nothing compares the total bytes received against the length the command asked for: struct nvme_tcp_request has no receive-side counter, queue->data_remaining is per queue, and blk_mq_end_request() completes for blk_rq_bytes(rq) unconditionally with no residual concept anywhere above. A controller can therefore answer a 4096-byte read with 512 bytes and have it reported as a complete read; user space then gets 4096 bytes of which 3584 are whatever was already in the page. I reproduced that with a test target. Count the bytes received and refuse to complete a successful read whose count does not match, at the two NVME_TCP_F_DATA_SUCCESS paths and in nvme_tcp_process_nvme_cqe(). The success test shifts req->status right by one, because the driver keeps the wire value there and shifts it on completion, so the check must see what the completion path will see. Only REQ_OP_READ is checked, because there the length comes from the sectors the request covers; a passthrough command is built by its submitter, which picks both command and buffer, so the kernel has nothing to compare against.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 36% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LI
Linux · Linux
3f2304f8c6d6ed97849057bd16fee99e434ca796 before a5c1bb0fb1bab2f24a081339c145870697f6d220; 3f2304f8c6d6ed97849057bd16fee99e434ca796 before aa107e3a68f4af177d60f2d87679e7f67179a36c; 3f2304f8c6d6ed97849057bd16fee99e434ca796 before fca3ebb63e5c82561cd9934365dcc0d068008006; 3f2304f8c6d6ed97849057bd16fee99e434ca796 before 99066cf9bba175f610ceb61a35f6fc9fbc33ff65; 3f2304f8c6d6ed97849057bd16fee99e434ca796 before 8a02ad98798fd01f51f648c1fdd8f3c9d07195d3; 3f2304f8c6d6ed97849057bd16fee99e434ca796 before 832a685efeb5d925ee7d30011d2dbe45f81447a3; +2 more · source: vendor