CVE-2026-31464

Description

In the Linux kernel, the following vulnerability has been resolved: scsi: ibmvfc: Fix OOB access in ibmvfc_discover_targets_done() A malicious or compromised VIO server can return a num_written value in the discover targets MAD response that exceeds max_targets. This value is stored directly in vhost->num_targets without validation, and is then used as the loop bound in ibmvfc_alloc_targets() to index into disc_buf[], which is only allocated for max_targets entries. Indices at or beyond max_targets access kernel memory outside the DMA-coherent allocation. The out-of-bounds data is subsequently embedded in Implicit Logout and PLOGI MADs that are sent back to the VIO server, leaking kernel memory. Fix by clamping num_written to max_targets before storing it.

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CVSS v3.1 Score

8.1

HIGH

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

EPSS — Exploit Prediction

0.0003

Probability of exploitation

0.08%

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.

Weakness Type (CWE)

CWE-125 Out-of-bounds Read

Affected Products

Vendor	Product	Versions
linux	linux_kernel	2.6.27 — 5.10.253
linux	linux_kernel	5.11 — 5.15.203
linux	linux_kernel	5.16 — 6.1.168
linux	linux_kernel	6.2 — 6.6.131
linux	linux_kernel	6.7 — 6.12.80
linux	linux_kernel	6.13 — 6.18.21
linux	linux_kernel	6.19 — 6.19.11
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All

References

Advisories & Patches

https://git.kernel.org/stable/c/394a1cac3c12fdd7d77f19ccfd222ab5ff87ef89 https://git.kernel.org/stable/c/4ed727e35b0ab17d3eeeb1e8023768396e2be161 https://git.kernel.org/stable/c/61d099ac4a7a8fb11ebdb6e2ec8d77f38e77362f https://git.kernel.org/stable/c/786f10b1966e485046839f992e89f2c18cbd1983 https://git.kernel.org/stable/c/a007246cb6c9ebdc93dafbf63cc2d43d98f402cc https://git.kernel.org/stable/c/bae4df0a643fa7f84663473aa3082a9c2ed139db https://git.kernel.org/stable/c/d1466bf991b2343cf2ba8336e440c8faf3cbb780 https://git.kernel.org/stable/c/d842348f8a00d5b1d7358f207eb34ffcf5b16df3

Frequently Asked Questions

What is CVE-2026-31464? +

In the Linux kernel, the following vulnerability has been resolved: scsi: ibmvfc: Fix OOB access in ibmvfc_discover_targets_done() A malicious or compromised VIO server can return a num_written value in the discover targets MAD response that exceeds max_targets. This value is stored directly in vhost->num_targets without validation, and is then used as the loop bound in ibmvfc_alloc_targets() to index into disc_buf[], which is only allocated for max_targets entries. Indices at or beyond max_targets access kernel memory outside the DMA-coherent allocation. The out-of-bounds data is subsequently embedded in Implicit Logout and PLOGI MADs that are sent back to the VIO server, leaking kernel memory. Fix by clamping num_written to max_targets before storing it. It has a CVSS v3.1 base score of 8.1 (HIGH).

How severe is CVE-2026-31464? +

CVE-2026-31464 has a CVSS v3.1 score of 8.1 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0003, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-31464? +

CVE-2026-31464 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-31464? +

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.

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