CVE-2026-81011 platform/x86: hp-bioscfg: pass validated element count to package parsers
A logic error in the HP BIOS configuration driver could lead to out-of-bounds heap reads if package validation is relaxed, potentially exposing kernel memory.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-81011?
CVE-2026-81011 is a high-severity memory corruption vulnerability in Linux, published on 11 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-81011?
How do I fix CVE-2026-81011?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-81011 being exploited?
There is no known exploitation of CVE-2026-81011 in the wild and no public exploit code.
Sources
Also known as AZL-100598, BELL-CVE-2026-81011, DEBIAN-CVE-2026-81011, GHSA-9rrq-fppg-695h, UBUNTU-CVE-2026-81011.