High severity · published Sep 11, 2026
CVE-2026-89481
nvme-tcp: fix host memory disclosure on R2T for a read command
7.5
CVSS
0.4%
EPSS
No
On KEV
Description
In the Linux kernel, the following vulnerability has been resolved:
nvme-tcp: fix host memory disclosure on R2T for a read command
nvme_tcp_handle_r2t() does not check the direction of the request the
R2T refers to. A malicious controller can send an R2T for a READ and
the host will answer it: nvme_tcp_setup_h2c_data_pdu() builds the
H2CData header and nvme_tcp_try_send_data() sends the request's data
buffer. That buffer is the READ destination, so its contents go to the
controller.
The command then completes normally and nothing is logged.
Against a test controller that answers every READ with an R2T, a 4096
byte buffered read returned all 4096 bytes, split over two R2Ts. The
pages contained stale kernel data, including an array of struct page
pointers.
Reject an R2T for a request that is not a write.
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 35% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LI
Linux · Linux
3f2304f8c6d6ed97849057bd16fee99e434ca796 before 49a4dcf57608ebf6432dbcb203ed25e7ed581445; 3f2304f8c6d6ed97849057bd16fee99e434ca796 before bc4013c7cce58d46f792c8c87bc8c8318a70190e; 3f2304f8c6d6ed97849057bd16fee99e434ca796 before a4c3c7310156493797c920b10d8648c07aa05403; 3f2304f8c6d6ed97849057bd16fee99e434ca796 before 3b3d27670c0c890ba7cf1bc3614cab61bde6d25c; 3f2304f8c6d6ed97849057bd16fee99e434ca796 before 3a0b05145053a5fad1a2ddb4e4d87b07385e63e5; 3f2304f8c6d6ed97849057bd16fee99e434ca796 before 6efbc52237facda35d2d874fe1765bb4839275d8; +1 more · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-89481
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-89481
git.kernel.org
https://git.kernel.org/stable/c/3a0b05145053a5fad1a2ddb4e4d87b07385e63e5
git.kernel.org
https://git.kernel.org/stable/c/3b3d27670c0c890ba7cf1bc3614cab61bde6d25c
git.kernel.org
https://git.kernel.org/stable/c/49a4dcf57608ebf6432dbcb203ed25e7ed581445
git.kernel.org
https://git.kernel.org/stable/c/6efbc52237facda35d2d874fe1765bb4839275d8
git.kernel.org
https://git.kernel.org/stable/c/a4c3c7310156493797c920b10d8648c07aa05403
git.kernel.org
https://git.kernel.org/stable/c/bc4013c7cce58d46f792c8c87bc8c8318a70190e
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