---
id: "CVE-2026-41221"
page: "https://infrastack.ai/live/CVE-2026-41221"
kind: "vulnerability"
aliases: ["CVE-2026-41221"]
title: "Intel Slim Bootloader UEFI firmware integer overflow allows privilege escalation"
severity: "high"
cvss: 8.6
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: [{"name": "slim-bootloader", "fixed": ["commit 9e77d9abb867e7ab4fec8249035cf9ba6550aed7 or later"], "affected": "builds before commit 9e77d9abb867e7ab4fec8249035cf9ba6550aed7 (July 7th, 2026)", "ecosystem": "vendor"}]
ecosystems: []
tags: ["bare-metal", "embedded", "infrastructure", "intel", "physical-access", "slim-bootloader", "uefi-firmware"]
not_affected_if: ["no-physical-access", "not-slim-bootloader", "unknown"]
published_at: "2026-11-10T18:17:38+00:00"
first_seen_at: "2026-11-10T18:22:57+00:00"
updated_at: "2026-11-10T18:29:01+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-41221", "first_seen_at": "2026-11-10T18:22:57+00:00"}, {"source": "analyst", "url": "https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-01526.html", "first_seen_at": "2026-11-10T18:29:01+00:00", "cites": ["https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-01526.html"]}]
exploit_sources: []
---

# Intel Slim Bootloader UEFI firmware integer overflow allows privilege escalation

Link for people: https://infrastack.ai/live/CVE-2026-41221 (this .md is for agents)

An integer overflow in the UEFI firmware of Intel's Slim Bootloader lets code running at firmware or System Management Mode level escalate privileges on the machine. The sources say an attacker with physical access and low complexity could gain full control of confidentiality, integrity and availability.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:slim-bootloader affected builds before commit 9e77d9abb867e7ab4fec8249035cf9ba6550aed7 (July 7th, 2026) fixed commit 9e77d9abb867e7ab4fec8249035cf9ba6550aed7 or later

## How to check

Find the Slim Bootloader commit/build your device firmware was built from (ask your board or device vendor, or check the SBL build info) and see whether it predates commit 9e77d9abb867e7ab4fec8249035cf9ba6550aed7 (July 7th, 2026). Intel lists platforms: Alder Lake, Twin Lake, Apollo Lake, Arrow Lake, Bartlett Lake-S, Coffee Lake, Comet Lake, Elkhart Lake, Ice Lake-D, Granite Rapids-D, Meteor Lake, Panther Lake, Raptor Lake, Tiger Lake. Only devices actually booting Slim Bootloader matter.

## Fix

Update Intel Slim Bootloader to the build at commit hash 9e77d9abb867e7ab4fec8249035cf9ba6550aed7 (from July 7th, 2026) or later; firmware updates come through your board/device vendor.

## Timeline

- 2026-11-10T18:22:57+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-41221
- 2026-11-10T18:29:01+00:00 analyst https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-01526.html — Found Intel INTEL-SA-01526 (11/10/2026, also CVE-2026-35500/41224/50175/44624/28746). Fix is a commit hash, no version numbers; affected list is by processor platform.

## Documents

- [advisory] INTEL-SA-01526 Intel Slim Bootloader Advisory https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-01526.html

## From the sources

Integer overflow in the UEFI firmware for the Intel(R) Slim Bootloader within Ring 0: Bare Metal OS may allow an escalation of privilege. Startup code and smm adversary with an unauthenticated user combined with a low complexity attack may enable escalation of privilege. This result may potentially occur via physical access when attack requirements are not present without special internal knowledge and requires no user interaction. The potential vulnerability may impact the confidentiality (high), integrity (high) and availability (high) of the vulnerable system, resulting in subsequent system confidentiality (high), integrity (high) and availability (high) impacts.

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