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
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-89480
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-89480
git.kernel.org
https://git.kernel.org/stable/c/7fa3f73f6c8ddc5f0425b50fb2a626a782ef7d12
git.kernel.org
https://git.kernel.org/stable/c/832a685efeb5d925ee7d30011d2dbe45f81447a3
git.kernel.org
https://git.kernel.org/stable/c/8a02ad98798fd01f51f648c1fdd8f3c9d07195d3
git.kernel.org
https://git.kernel.org/stable/c/99066cf9bba175f610ceb61a35f6fc9fbc33ff65
git.kernel.org
https://git.kernel.org/stable/c/a5c1bb0fb1bab2f24a081339c145870697f6d220
git.kernel.org
https://git.kernel.org/stable/c/aa107e3a68f4af177d60f2d87679e7f67179a36c
More from Linux
9.8
CVE-2025-39682
tls: fix handling of zero-length records on the rx_list
8.8
CVE-2026-53266
netfilter: bridge: make ebt_snat ARP rewrite writable
7.8
CVE-2026-53362
ipv6: account for fraggap on the paged allocation path
7.8
CVE-2026-46300
net: skbuff: preserve shared-frag marker during coalescing
7.8
CVE-2026-31431
crypto: algif_aead - Revert to operating out-of-place
