CVE-2026-89481 (CVSS 7.5)

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.

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CVSS v3.1 Score

7.5

HIGH

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

EPSS — Exploit Prediction

0.0041

Probability of exploitation

0.35%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

References

Other References

https://git.kernel.org/stable/c/3a0b05145053a5fad1a2ddb4e4d87b07385e63e5 https://git.kernel.org/stable/c/3b3d27670c0c890ba7cf1bc3614cab61bde6d25c https://git.kernel.org/stable/c/49a4dcf57608ebf6432dbcb203ed25e7ed581445 https://git.kernel.org/stable/c/6efbc52237facda35d2d874fe1765bb4839275d8 https://git.kernel.org/stable/c/a4c3c7310156493797c920b10d8648c07aa05403 https://git.kernel.org/stable/c/bc4013c7cce58d46f792c8c87bc8c8318a70190e

Frequently Asked Questions

What is CVE-2026-89481? +

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. It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2026-89481? +

CVE-2026-89481 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0041, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-89481? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

CVE-2026-89481