# CVE-2026-41221: Intel Slim Bootloader integer overflow in UEFI firmware

Source: https://junglewise.ai/threats/cve-2026-41221-integer-overflow-in-the-uefi-firmware-for-the-intel-r-slim  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-10. Updated: 2026-11-10  
License: CC BY 4.0 with a link back

CVE-2026-41221 · Severity: info · Published 2026-11-10

The Intel Slim Bootloader is firmware that runs during system startup before the operating system loads. An integer overflow flaw in this bootloader allows an attacker with physical access to escalate privileges and gain complete control of the system, compromising its confidentiality, integrity, and availability. No user interaction or authentication is required to exploit this vulnerability.

Technologies: [Intel Processor N-series](https://junglewise.ai/threats/technologies/processor-n-series), [Intel Slim Bootloader](https://junglewise.ai/threats/technologies/slim-bootloader). Vendors: [Intel](https://junglewise.ai/threats/vendors/intel).

## Quick answers

**Is CVE-2026-41221 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-41221 being exploited in the wild.

**How severe is CVE-2026-41221?** Informational severity, published 10 November 2026.

**Which products and versions are affected?** Intel 12th Generation Core Processor Alder Lake (906A3, 906A4); Intel Celeron Processor Family Alder Lake; Intel Pentium Gold Processor Family Alder Lake; Intel Processor N-series Twin Lake; and 1 more.

**Is there a fix for CVE-2026-41221?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-41221 attacked?** It is attacked with physical access, in device firmware.

**Am I affected by CVE-2026-41221?** Check whether you run Intel 12th Generation Core Processor, Intel Celeron Processor Family, Intel Pentium Gold Processor Family or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

An integer overflow vulnerability exists in the UEFI firmware component of Intel Slim Bootloader running at Ring 0 privilege level. An attacker with physical access can trigger this flaw in the startup code or SMM (System Management Mode) to achieve privilege escalation. The vulnerability requires no authentication or user interaction, allowing complete compromise of system confidentiality, integrity, and availability.

## Affected products

- Intel Slim Bootloader Versions affecting 12th Generation Core, Pentium Gold, Celeron, and Processor N-series
- Intel 12th Generation Core Processor Alder Lake (906A3, 906A4)
- Intel Pentium Gold Processor Family Alder Lake
- Intel Celeron Processor Family Alder Lake
- Intel Processor N-series Twin Lake

## Timeline

- 2026-11-10: disclosed

## References

- [https://intel.com/content/www/us/en/security-center/advisory/intel-sa-01526.html](https://intel.com/content/www/us/en/security-center/advisory/intel-sa-01526.html)

## Related threats

- [Intel Slim Bootloader pointer dereference in FirmwareWakingVector](https://junglewise.ai/threats/cve-2026-50175-untrusted-pointer-dereference-in-the-firmwarewakingvector-for-the)
- [Intel Slim Bootloader Ext2 parser incorrect comparison](https://junglewise.ai/threats/cve-2026-44624-incorrect-comparison-in-the-ext2-parser-for-the-intel-r-slim)
- [Intel Slim Bootloader out-of-bounds write privilege escalation](https://junglewise.ai/threats/cve-2026-41224-out-of-bounds-write-in-the-uefi-firmware-for-the-intel-r-slim)
- [Intel Slim Bootloader stack buffer overflow in Ring 0](https://junglewise.ai/threats/cve-2026-35500-stack-based-buffer-overflow-in-the-uefi-firmware-for-the-intel-r)
- [Intel Slim Bootloader out-of-bounds read in AuthenticateComponent](https://junglewise.ai/threats/cve-2026-28746-out-of-bounds-read-in-the-authenticatecomponent-for-the-intel-r)