Linux KernelOperating system · Linux

CVE-2026-43200

MEDIUM · 5.5 CVSS v3.1 Published 2026-05-06
Fix available
A fix is available. Upgrade to 5.15.202 / 6.1.165 or later.
See remediation →
57/100
Remediation priority · Elevated
Zero-click Patch available

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 · unedited
In the Linux kernel, the following vulnerability has been resolved: PCI: endpoint: Fix swapped parameters in pci_{primary/secondary}_epc_epf_unlink() functions struct configfs_item_operations callbacks are defined like the following: int (*allow_link)(struct config_item *src, struct config_item *target); void (*drop_link)(struct config_item *src, struct config_item *target); While pci_primary_epc_epf_link() and pci_secondary_epc_epf_link() specify the parameters in the correct order, pci_primary_epc_epf_unlink() and pci_secondary_epc_epf_unlink() specify the parameters in the wrong order, leading to the below kernel crash when using the unlink command in configfs: Unable to handle kernel paging request at virtual address 0000000300000857 Mem abort info: ... pc : string+0x54/0x14c lr : vsnprintf+0x280/0x6e8 ... string+0x54/0x14c vsnprintf+0x280/0x6e8 vprintk_default+0x38/0x4c vprintk+0xc4/0xe0 pci_epf_unbind+0xdc/0x108 configfs_unlink+0xe0/0x208+0x44/0x74 vfs_unlink+0x120/0x29c __arm64_sys_unlinkat+0x3c/0x90 invoke_syscall+0x48/0x134 do_el0_svc+0x1c/0x30prop.0+0xd0/0xf0 [mani: cced stable, changed commit message as per https://lore.kernel.org/linux-pci/aV9joi3jF1R6ca02@ryzen]

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

A detailed technical summary for this CVE is being prepared.

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
Affected:>= 5.12, < 5.15.202>= 5.16, < 6.1.165>= 6.2, < 6.6.128>= 6.7, < 6.12.75>= 6.13, < 6.18.16>= 6.19, < 6.19.6

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
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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 · scoped
Upgrade available Upgrade to 5.15.202 / 6.1.165 / 6.6.128 or later
Fixed in 5.15.2026.1.1656.6.128
Vendor patch git.kernel.org →
Recommended fix High confidence

Upgrade to one of: Linux 5.15.202, 6.1.165, 6.6.128, or 6.12.75 (or later stable release)

  1. Identify the current kernel version using 'uname -r'
  2. Navigate to the Linux kernel source directory (or download the source)
  3. Locate the file containing pci_primary_epc_epf_unlink() and pci_secondary_epc_epf_unlink() functions - typically in drivers/pci/endpoint/
  4. Apply the fix by swapping the parameter order in both functions to match the configfs_item_operations expected signature: src (struct config_item *src, struct config_item *target)
  5. Alternatively, apply the upstream commit directly: git cherry-pick 142b1bba3299264b76ed8ef53cd93b2b2af65d6c
  6. Rebuild the kernel modules or kernel as appropriate for the PCI endpoint code
  7. Reboot or reload the pci_epc and pci_epf modules to load the fixed code
Caveat Kernel upgrades may introduce other changes; test in non-production environment first

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $1,600. Get the upgrade done

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-43200 in production — separate from our analysis above.

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What this is

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