# CVE-2026-81013

## Summary

- **CVE ID:** CVE-2026-81013
- **Severity:** UNKNOWN
- **CVSS Score:** 0
- **CWE:** N/A
- **Published:** Sep 11, 2026
- **Last Modified:** Sep 16, 2026

## Description

In the Linux kernel, the following vulnerability has been resolved:

platform/x86: hp-bioscfg: fix heap OOB read on empty password write

validate_password_input() computes length = strlen(buf) and then
checks buf[length - 1] to strip a trailing newline, without checking
that length is nonzero first. Writing an empty string (a bare '\n')
to current_password or new_password gives length == 0, and
buf[length - 1] reads buf[-1], one byte before the heap allocation
holding the copied input.

KASAN confirms this directly:

  BUG: KASAN: slab-out-of-bounds in store_password_instance.constprop.0+0x223/0x2a0 [hp_bioscfg]
  Read of size 1 at addr ffff88811bd8da9f by task sh/13740
  ...
  store_password_instance.constprop.0+0x223/0x2a0 [hp_bioscfg]
  current_password_store+0x14/0x20 [hp_bioscfg]
  ...
  The buggy address is located 23 bytes to the right of
  allocated 8-byte region [ffff88811bd8da80, ffff88811bd8da88)

Reproduced identically via new_password_store. Execution continues
past the bad read (the garbage byte only affects whether "length" is
decremented by one), so the write completes and returns success; this
is a pure information read past the buffer, not a crash, but it is
still an out-of-bounds access KASAN correctly flags.

Fix by only checking buf[length - 1] when length is nonzero.

## Affected Products

- Linux — Linux (8646a3b5ee3a5b384a22a721f37c24274d974045)
- Linux — Linux (6.6)
- Linux — Linux (0)
- Linux — Linux (6.12.109)
- Linux — Linux (6.18.50)
- Linux — Linux (7.2.4)
- Linux — Linux (7.3-rc1)
- Linux — Linux (6.6.157)

## References

- [CNA](https://git.kernel.org/stable/c/cecb8154bd5fa6c8ddbd1a4e8216bbc0f0eb9828)
- [CNA](https://git.kernel.org/stable/c/0f9aad08424882dd5714b53d29ae044060890752)
- [CNA](https://git.kernel.org/stable/c/b699e5c1f63a9e79946c35598c8a6f7af2c356b8)
- [CNA](https://git.kernel.org/stable/c/2b2ec354f905c14e3270e8ec3ab50f7d8ad73bab)
- [CNA](https://git.kernel.org/stable/c/21243c15e1d31f0df1517435e3a7784747f19043)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.18%
- **EPSS Percentile:** 7.9

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-17._