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Linux KernelOperating system · Linux

CVE-2026-53247

CRITICAL · 9.8 CVSS v3.1 Published 2026-06-25
Fix available
A fix is available. Upgrade to 6.6.143 / 6.12.94 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges 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: net: ethernet: mtk_eth_soc: Fix use-after-free in metadata dst teardown mtk_free_dev() calls metadata_dst_free() which frees the metadata_dst with kfree() immediately, bypassing the RCU grace period. In the RX path, skb_dst_set_noref() sets a non-refcounted pointer from the skb to the metadata_dst. This function requires RCU read-side protection and the dst must remain valid until all RCU readers complete. Since metadata_dst_free() calls kfree() directly, a use-after-free can occur if any skb still holds a noref pointer to the dst when the driver tears it down. Replace metadata_dst_free() with dst_release() which properly goes through the refcount path: when the refcount drops to zero, it schedules the actual free via call_rcu_hurry(), ensuring all RCU readers have completed before the memory is freed.

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 · high confidence

A use-after-free vulnerability exists in the MediaTek ethernet driver (mtk_eth_soc) where mtk_free_dev() calls metadata_dst_free() which uses kfree() directly without waiting for RCU grace periods. The RX path uses skb_dst_set_noref() to set non-refcounted pointers to the metadata_dst, so if any skb still references the dst when the driver tears it down, a use-after-free occurs.

MitigationReplace metadata_dst_free() with dst_release() in the driver to ensure proper refcount handling and RCU grace period waiting before freeing the metadata_dst structure.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

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:>= 6.2, < 6.6.143>= 6.7, < 6.12.94>= 6.13, < 6.18.36>= 6.19, < 7.0.13= 7.1

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
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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 checks

Work through these to decide whether this CVE applies to you.

  1. Check kernel version
    Run 'uname -r' to get the running kernel version
    Affected if The kernel version falls within any of these ranges: >=6.2 and <6.6.143, >=6.7 and <6.12.94, >=6.13 and <6.18.36, >=6.19 and <7.0.13, or equals 7.1
  2. Identify mtk_eth_soc driver presence
    Run 'lsmod | grep mtk_eth' or check 'modinfo mtk_eth_soc' to see if the MediaTek ethernet driver is loaded or available
    Affected if The mtk_eth_soc driver is loaded on the system
  3. Verify network interface uses MediaTek hardware
    Run 'ip link show' and 'lspci | grep -i ethernet' or check 'ethtool -i <interface>' to identify network interfaces backed by MediaTek hardware
    Affected if Any network interface is provided by a MediaTek ethernet controller using the mtk_eth_soc driver
  4. Confirm the vulnerable code path exists
    Check the driver source file (drivers/net/ethernet/mediatek/mtk_eth_soc.c) for the mtk_free_dev() function and verify it uses metadata_dst_free() instead of dst_release()
    Affected if The mtk_free_dev() function contains a call to metadata_dst_free()

The system is affected if it runs a vulnerable kernel version within the specified ranges AND uses the mtk_eth_soc driver with MediaTek ethernet hardware, where the driver code still contains the problematic metadata_dst_free() call in mtk_free_dev().

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 6.6.143 / 6.12.94 / 6.18.36 or later
Fixed in 6.6.1436.12.946.18.36
Vendor patch git.kernel.org →
Interim mitigation

Replace metadata_dst_free() with dst_release() in the driver to ensure proper refcount handling and RCU grace period waiting before freeing the metadata_dst structure.

Recommended fix High confidence

6.6.143, 6.12.94, 6.18.36, or 7.0.13 (whichever branch is currently in use)

  1. Upgrade Linux kernel to version 6.6.143 or later for the 6.6.y branch
  2. Alternatively, upgrade to version 6.12.94 or later for the 6.7.y-6.12.y branch
  3. Alternatively, upgrade to version 6.18.36 or later for the 6.13.y-6.18.y branch
  4. Alternatively, upgrade to version 7.0.13 or later for the 6.19.y-7.0.y branch
  5. After kernel upgrade, verify the mtk_eth_soc driver is loaded and functioning correctly
Caveat Kernel upgrades may require rebuilding out-of-tree modules; ensure any proprietary drivers are compatible with the new kernel version

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

Fix this in Linux Kernel Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA3.0 h
15.0 hours of engineering $2,560
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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-2026-53247 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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