# CVE-2026-97876: grub2: A local attacker with control over GRUB's configuration can bypass lockdown restrictions when booting with Secure Boo...

CVE-2026-97876 is fixed in grub2 on 1 platform by DEBIAN-CVE-2026-97876 (version 2.14-4), released October 6, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-97876
- Priority: Routine
- CVSS: 6.4 (medium)
- EPSS: 0.0012
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Oct 2, 2026

## Description

A local attacker with control over GRUB's configuration can bypass lockdown restrictions when booting with Secure Boot and load an unsigned GRUB module, while GRUB continues to report lockdown is enabled.     The vulnerability is caused by insufficient validation of the MMIO base address passed to the GRUB serial command. GRUB does not validate that the base address corresponds to a UART device, rather than being an arbitrary memory address. This allows an attacker to trick GRUB into writing non-arbitrary data at an attacker-controlled address, including resetting the grub_file_verifiers list in a way that disables the subsequent verification of loaded modules.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | grub2 Debian 14 | 2.14-4 | [DEBIAN-CVE-2026-97876](https://patchblox.com/security/data/fix/linux/debian-cve-2026-97876.md) | Oct 6, 2026 |

---

Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data

Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.