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CVE-2026-53247 Linux CVE debrief

CVE-2026-53247 is a critical vulnerability in the Linux kernel's mtk_eth_soc component. The vulnerability is caused by a use-after-free error in the metadata dst teardown process. This occurs when the mtk_free_dev() function calls metadata_dst_free(), which frees the metadata_dst with kfree() immediately, bypassing the RCU grace period. As a result, a use-after-free can occur if any skb still holds a noref pointer to the dst when the driver tears it down. The Common Vulnerability Scoring System (CVSS) scores this vulnerability as 9.8, indicating a high severity. The vulnerability was published on June 25, 2026, and last modified on June 28, 2026.

Vendor
Linux
Product
Unknown
CVSS
CRITICAL 9.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-25
Original CVE updated
2026-07-07
Advisory published
2026-06-25
Advisory updated
2026-07-07

Who should care

This vulnerability affects Linux kernel users, particularly those using the mtk_eth_soc component. System administrators and security teams should be aware of this vulnerability and take necessary steps to mitigate it. Linux distribution maintainers and kernel developers should also be aware of this vulnerability and apply the necessary patches.

Technical summary

The vulnerability is caused by a use-after-free error in the metadata dst teardown process. The mtk_free_dev() function calls metadata_dst_free(), which frees the metadata_dst with kfree() immediately, bypassing the RCU grace period. This can cause a use-after-free error if any skb still holds a noref pointer to the dst when the driver tears it down. The fix is to replace metadata_dst_free() with dst_release(), which properly goes through the refcount path and ensures that all RCU readers have completed before the memory is freed.

Defensive priority

High priority should be given to patching this vulnerability, as it has a high CVSS score and can be exploited remotely. Linux kernel users should apply the necessary patches as soon as possible.

Recommended defensive actions

  • Apply the patch from the Linux kernel repository that replaces metadata_dst_free() with dst_release().
  • Review and update Linux kernel configurations to ensure that the mtk_eth_soc component is properly configured and secured.
  • Monitor system logs for potential exploitation attempts.
  • Consider implementing additional security controls, such as network segmentation and access controls, to limit the attack surface.
  • Keep Linux kernel and distribution up to date with the latest security patches.

Evidence notes

The CVE record and NVD detail provide information on the vulnerability, including its description, CVSS score, and references. The Linux kernel repository provides the patch that fixes the vulnerability.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-53247 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-53247

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-53247 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-53247

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/2d86aeb46d5f69c704065a8c69822582787272a1

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/459c6f35c58cf0fd5247e55d73ddaa29571d9b7e

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/72775977e89c25c99ee84d2c5baa3f86a8ba5cb4

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/80df409e1a483676826a6c66e693dba6ac507751

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/e634408d2b0cd939cfe019398a21fb47b7a8ffe3

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.