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PatchSiren cyber security CVE debrief

CVE-2026-74704 Linux CVE debrief

A vulnerability in the Linux kernel's sch_cake component can cause a denial of service due to excessive warnings in the system's logs when handling malformed packets. The vulnerability has been resolved by removing the WARN_ON(1) statement. Linux system administrators and maintainers should assess exposure and apply patches as necessary to prevent denial of service due to excessive warnings. The sch_cake component is used for traffic shaping and policing, and the vulnerability can be triggered by a malformed IP header in certain cases.

Vendor
Linux
Product
Unknown
CVSS
HIGH 8.2
CISA KEV
Not listed in stored evidence
Original CVE published
2026-08-22
Original CVE updated
2026-10-16
Advisory published
2026-08-22
Advisory updated
2026-10-16

Who should care

Linux system administrators and maintainers should assess exposure and apply patches as necessary to prevent denial of service due to excessive warnings. The vulnerability can cause a denial of service due to excessive warnings in the system's logs, and the sch_cake component is used for traffic shaping and policing.

Why it matters

Linux system administrators and maintainers should assess exposure and apply patches as necessary to prevent denial of service due to excessive warnings.

  • Denial of service due to excessive warnings
  • Potential system log flooding and analysis overhead

Technical summary

The Linux kernel's sch_cake component is vulnerable to excessive warnings due to malformed packets. The vulnerability has been resolved by removing the WARN_ON(1) statement. The sch_cake component is used for traffic shaping and policing, and the vulnerability can be triggered by a malformed IP header in certain cases. The vulnerability can cause a denial of service due to excessive warnings in the system's logs. Linux system administrators and maintainers should assess exposure and apply patches as necessary to prevent denial of service due to excessive warnings.

Defensive priority

Medium

Recommended defensive actions

  • Review system logs for excessive warnings related to the sch_cake component
  • Verify Linux kernel versions and apply patches as necessary
  • Monitor system stability and performance
  • Check relevant monitoring, detection, and logs for exposed assets that need extra review
  • Track exceptions, retest remediated assets, and close the item only after evidence is documented
  • Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
  • Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance

Evidence notes

The CVE record and Linux kernel source code indicate that the sch_cake component is vulnerable to excessive warnings due to malformed packets. The Linux kernel maintainers have resolved the issue by removing the WARN_ON(1) statement. The vulnerability can be triggered by a malformed IP header in certain cases, and the sch_cake component is used for traffic shaping and policing.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-74704 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-74704

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

  • CVE-2026-74704 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-74704

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

Supplemental references

  • net/sched: sch_cake: drop WARN_ON(1) for malformed packets in ACK filter

    Unverified legacy reference

    URL: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/74xxx/CVE-2026-74704.json

    cve_program_cvelist_v5

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/c1693b7844a6c06d31a565e5a494948034dfd235

    Supplemental source

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/a4b52612004a5639c4bfc30ba93ba414b8326e2a

    Supplemental source

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/ae1b2f8e21a41e7c7e75511bea0c4ccc59ec1bd3

    Supplemental source

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/0c4882bff34558d8d53fb04c3e96da5c327c7dc8

    Supplemental source

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/2504a76e5c0694e14e15562730e1339f2d9f9458

    Supplemental source

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/cd2f1d9fe8a507c2dc86ad326fe221f121c47734

    Supplemental source

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/a1ae353d8355407c1bea971d1c1af5e7f242bb7d

    Supplemental source

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.