CVE-2026-97876

NameCVE-2026-97876
DescriptionA 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 resettingĀ the grub_file_verifiers list in a way that disables the subsequent verification of loaded modules.
SourceCVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
Debian Bugs1148741

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
grub2 (PTS)bookworm2.06-13+deb12u2vulnerable
bookworm (security)2.06-13+deb12u1vulnerable
trixie2.12-9+deb13u2vulnerable
forky2.14-3vulnerable
sid2.14-4fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
grub2source(unstable)2.14-41148741

Notes

https://www.openwall.com/lists/oss-security/2026/09/13/5
Fixed by: https://gitlab.freedesktop.org/gnu-grub/grub/-/commit/26beaa3b2720fefdc4d04c1ae209b776fe6848d6 (grub-2.16)

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