VulnerabilityPublished 11 Sep 2026Updated 30 Oct 2026

CVE-2026-89481: Linux kernel · nvme-tcp: fix host memory disclosure on R2T for a read command

Affects Linux kernelSource CVE Database V5

Not known to be exploited · CVSS 7.5 High · fixed in effe898669c5f69ed519d6339be01ee9cd91d1a4 : patch Linux kernel soon.

Data as of 30 Oct 2026, 13:04 UTC

CVSS 3.1 base score

7.5High

How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none

CVSS scores by source
CNA (Linux)	CVSS 3.1	7.5

Exploitation: No evidence of active exploitation and no public proof of concept
Automatable: Attackers can reliably automate steps 1–4 of the kill chain
Technical impact: Limited control over the software or limited information exposure

CISA SSVC assessment, 2026-10-16.

Patch

Available – fixed in effe898669c5f69ed519d6339be01ee9cd91d1a4, bc4013c7cce58d46f792c8c87bc8c8318a70190e, a4c3c7310156493797c920b10d8648c07aa05403 +5

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: None
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 11 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 3f2304f8c6d6ed97849057bd16fee99e434ca796, < effe898669c5f69ed519d6339be01ee9cd91d1a4	Fixed in effe898669c5f69ed519d6339be01ee9cd91d1a4
LinuxLinux	Affected ≥ 3f2304f8c6d6ed97849057bd16fee99e434ca796, < bc4013c7cce58d46f792c8c87bc8c8318a70190e	Fixed in bc4013c7cce58d46f792c8c87bc8c8318a70190e
LinuxLinux	Affected ≥ 3f2304f8c6d6ed97849057bd16fee99e434ca796, < a4c3c7310156493797c920b10d8648c07aa05403	Fixed in a4c3c7310156493797c920b10d8648c07aa05403
LinuxLinux	Affected ≥ 3f2304f8c6d6ed97849057bd16fee99e434ca796, < 377aa04d7b3e73ffef6364818def188da8d6f025	Fixed in 377aa04d7b3e73ffef6364818def188da8d6f025
LinuxLinux	Affected ≥ 3f2304f8c6d6ed97849057bd16fee99e434ca796, < 49a4dcf57608ebf6432dbcb203ed25e7ed581445	Fixed in 49a4dcf57608ebf6432dbcb203ed25e7ed581445
LinuxLinux	Affected ≥ 3f2304f8c6d6ed97849057bd16fee99e434ca796, < 6efbc52237facda35d2d874fe1765bb4839275d8	Fixed in 6efbc52237facda35d2d874fe1765bb4839275d8

AI-suggested

This vulnerability has been fixed in the Linux kernel. Users should update to the fixed versions identified by the commits (e.g., effe898669c5f69ed519d6339be01ee9cd91d1a4 and others). No additional mitigation is required once the system is updated.

Description

CVE-2026-89481 is a vulnerability in the Linux kernel's nvme-tcp driver where the host memory can be disclosed due to improper handling of R2T (Ready To Transfer) packets for read commands. A malicious NVMe controller can exploit this by sending an R2T for a read request, causing the host to send back data from its read destination buffer, which may contain stale kernel memory. This issue is fixed by rejecting R2T packets for requests that are not writes.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 30 Oct 2026, 13:04 UTC

Technical details

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