CVE-2026-25828
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedgrub-btrfs through 2026-01-31 (on Arch Linux and derivative distributions) allows initramfs OS command injection because it does not sanitize the $root parameter to resolve_device(). NOTE: a third party reports "exploitation may not be feasible under normal conditions and may depend on specific implementation details within resolve_device."
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidencegrub-btrfs through 2026-01-31 contains a command injection vulnerability in the resolve_device() function where the $root parameter is not sanitized before use, potentially allowing OS command injection in the initramfs context. The third-party assessment notes exploitation may not be feasible under normal conditions and may depend on specific implementation details.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify installed grub-btrfs versionRun 'grub-btrfs --version' or check your package manager (dpkg -l grub-btrfs, rpm -qi grub-btrfs, or pacman -Qi grub-btrfs)Affected if The version date is 2026-01-31 or earlier, indicating it contains the unpatched vulnerable code
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Locate the grub-btrfs script containing resolve_device()Find the main grub-btrfs script, typically at /etc/grub.d/41_snapshots-btrfs or /usr/bin/grub-btrfs, then search for the resolve_device function definitionAffected if The resolve_device function exists and uses the $root variable directly in command execution without sanitization (e.g., no input validation or escaping of shell metacharacters)
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Verify btrfs snapshot listing is enabled in GRUBCheck /etc/default/grub for GRUB_BTRFS_SUBVOLUME or GRUB_BTRFS_SNAPSHOT_KERNEL parameters, or check if the 41_snapshots-btrfs script is executable in /etc/grub.d/Affected if Btrfs snapshot integration is enabled (the 41_snapshots-btrfs script is executable) and the system uses btrfs as root filesystem, as the vulnerability only applies when resolve_device() is invoked during boot
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Confirm btrfs is used as the root filesystemRun 'df / | tail -1' or 'mount | grep ' / ' to check if the root filesystem is btrfsAffected if The root filesystem is btrfs and grub-btrfs is actively used to list snapshots at boot time, meaning the vulnerable code path can be triggered
You are affected if grub-btrfs version is dated 2026-01-31 or earlier, btrfs is your root filesystem, and snapshot listing is enabled, causing the unsanitized $root parameter in resolve_device() to be processed during boot.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataUpdate grub-btrfs to a patched version that properly sanitizes the $root parameter in resolve_device(), or implement input validation to strip or escape shell metacharacters before the parameter is processed.
- Consultation3.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2026-25828 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-25828 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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