Linux KernelOperating system · Linux
CVE-2026-43278
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 · uneditedIn the Linux kernel, the following vulnerability has been resolved: dm: clear cloned request bio pointer when last clone bio completes Stale rq->bio values have been observed to cause double-initialization of cloned bios in request-based device-mapper targets, leading to use-after-free and double-free scenarios. One such case occurs when using dm-multipath on top of a PCIe NVMe namespace, where cloned request bios are freed during blk_complete_request(), but rq->bio is left intact. Subsequent clone teardown then attempts to free the same bios again via blk_rq_unprep_clone(). The resulting double-free path looks like: nvme_pci_complete_batch() nvme_complete_batch() blk_mq_end_request_batch() blk_complete_request() // called on a DM clone request bio_endio() // first free of all clone bios ... rq->end_io() // end_clone_request() dm_complete_request(tio->orig) dm_softirq_done() dm_done() dm_end_request() blk_rq_unprep_clone() // second free of clone bios Fix this by clearing the clone request's bio pointer when the last cloned bio completes, ensuring that later teardown paths do not attempt to free already-released bios.
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 analysisThe same block of memory is freed twice, corrupting the allocator's bookkeeping in ways an attacker can shape toward code execution. It usually stems from tangled ownership of a pointer. The fix is clear, single ownership of each allocation and clearing pointers once they are freed.
General guidance for the double free class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
Linux KernelOperating system
>= 6.1, < 6.1.165>= 6.2, < 6.6.128>= 6.7, < 6.12.75>= 6.13, < 6.18.16>= 6.19, < 6.19.6CVSS 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
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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.
dbcve · scoped6.1.1656.6.1286.12.75
Upgrade to kernel >=6.1.165 (6.1.x branch), >=6.6.128 (6.2-6.6.x branch), >=6.12.75 (6.7-6.12.x branch), or >=6.18.16 (6.13+ branch)
- 1. Identify the currently running Linux kernel version using `uname -r`
- 2. Determine which stable kernel branch your current version belongs to (6.1, 6.2, 6.7, or 6.13 series)
- 3. Upgrade the Linux kernel to the fixed version for your branch: for 6.1.x upgrade to >=6.1.165, for 6.2-6.6.x upgrade to >=6.6.128, for 6.7-6.12.x upgrade to >=6.12.75, or for 6.13-6.18.x upgrade to >=6.18.16
- 4. If using a distribution-provided kernel, update via the distribution's package manager (e.g., `apt update && apt upgrade linux-image-*` for Debian/Ubuntu, `yum update kernel` for RHEL/CentOS, or `dnf update kernel` for Fedora)
- 5. If building from source, apply the commit 7daf279c674d515fb22a727a7bbc92aeb35c5442 or use a kernel config with the fix incorporated
- 6. Reboot the system to load the patched kernel
- 7. Verify the fix is applied by checking `uname -r` shows a patched version and confirming the vulnerability is resolved
Generated from the published advisory — verify against the referenced sources before acting.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-43278 — 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-2026-43278 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
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