CVE-2026-53247: Linux Kernel use-after-free (CVSS 9.8)

Description

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.

CVSS 3.1 breakdown

Attack vectorNetwork

Attack complexityLow

Privileges requiredNone

User interactionNone

ScopeUnchanged

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

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

Affected products

Linux Kernel≥ 6.13 < 6.18.36 · ≥ 6.19 < 7.0.13 · ≥ 6.2 < 6.6.143 · ≥ 6.7 < 6.12.94

Remediation

Fixed in

Linux Kernel≥ 6.18.36

Patch & vendor advisories

References

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

Frequently asked

Is CVE-2026-53247 being actively exploited?

CVE-2026-53247 is not in the CISA KEV catalog. Its EPSS exploit probability is 0.69%.

How severe is CVE-2026-53247?

CVE-2026-53247 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 0.69% probability of exploitation.

Which products are affected by CVE-2026-53247?

Affected products include Linux Kernel.

How do I fix CVE-2026-53247?

Upgrade affected software to a fixed version, for example Linux Kernel 6.18.36 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-53247 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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