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PatchSiren cyber security CVE debrief

CVE-2026-31670 Linux CVE debrief

A MEDIUM severity vulnerability, CVE-2026-31670, was found in the Linux kernel. This issue allows userspace to create an unlimited number of rfkill events without consuming them, potentially leading to an out-of-memory situation. The kernel has been updated to limit the number of pending rfkill events to a large number, preventing such abuses. System administrators should review their kernel versions and update as necessary.

Vendor
Linux
Product
Unknown
CVSS
MEDIUM 5.5
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-14
Original CVE updated
2026-07-28
Advisory published
2026-07-14
Advisory updated
2026-07-28

Who should care

System administrators and users of Linux kernel versions prior to the patched versions should be aware of this vulnerability. Successful exploitation could lead to denial-of-service conditions due to memory exhaustion. Review compensating controls for exposed systems while remediation is scheduled and verified.

Technical summary

The Linux kernel was vulnerable to an issue where userspace could create an unlimited number of rfkill events without properly consuming them from the rfkill file descriptor. This could lead to a potential out-of-memory situation. The fix implemented a limit on the number of pending rfkill events to prevent such abuses. Affected systems should apply kernel updates to limit rfkill events and prevent potential memory exhaustion.

Defensive priority

Apply kernel updates to limit rfkill events and prevent potential memory exhaustion. Monitor system resources for signs of memory exhaustion and adjust limits as necessary. Consider implementing additional logging and monitoring to detect potential exploitation attempts. Restrict access to the rfkill file descriptor to prevent unauthorized creation of rfkill events. 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. Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed. Check relevant monitoring, detection, and logs for exposed assets that need extra review. Review compensating controls for exposed systems while remediation is scheduled and verified. Implement a robust patch management process to ensure timely updates. Conduct regular security audits to identify potential vulnerabilities. Engage with the Linux kernel community for updates on this vulnerability. Utilize threat intelligence to stay informed about potential exploitation attempts. Develop an incident response plan in case of exploitation. Provide training to staff on the importance of kernel updates and security patches. Establish a vulnerability management program to track and address vulnerabilities like CVE-2026-31670. Consider implementing a bug bounty program to encourage responsible disclosure of vulnerabilities. Collaborate with other organizations to share information about potential threats and vulnerabilities. Utilize security information and event management (SIEM) systems to monitor for suspicious activity. Implement a continuous monitoring program to detect and respond to security incidents in real-time. Develop a comprehensive risk management strategy to address potential vulnerabilities and threats. Conduct regular penetration testing and vulnerability assessments to identify potential weaknesses. Establish a governance framework to ensure accountability and oversight of IT

Recommended defensive actions

  • Apply the official patches or kernel updates provided by the Linux kernel maintainers.
  • Restrict access to the rfkill file descriptor to prevent unauthorized creation of rfkill events.
  • Monitor system resources for signs of memory exhaustion and adjust limits as necessary.
  • Consider implementing additional logging and monitoring to detect potential exploitation attempts.
  • 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.
  • Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed.

Evidence notes

The CVE record was published on 2026-04-24T15:16:46.790Z and was last modified on 2026-07-14T13:18:47.840Z. The NVD entry is currently Modified. This vulnerability affects Linux kernel versions prior to the patched versions. The fix implemented a limit on the number of pending rfkill events to prevent potential out-of-memory situations. Evidence is limited to public CVE and NVD information.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-31670 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-31670

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

  • CVE-2026-31670 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-31670

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

Supplemental references

  • Mitigation or vendor reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/4bcd1615a4e2a185ae9edd27b4143d7dfa7134f4

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

  • Mitigation or vendor reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/673d2a3eef6e0ee9736501a150c9e4024a4e60a6

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

  • Mitigation or vendor reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/80ce4cb026f0a4c4532b6cad827b44debda6256a

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

  • Mitigation or vendor reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/82843afc19012a29ba863961ef494165aa1a88f4

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

  • Mitigation or vendor reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/a8c26800e0220e1550af012f5a20e50f5c78864d

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

  • Mitigation or vendor reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/b1e0c8d3ab58a0161db487bf5fc47adfcaf5d5ca

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

  • Mitigation or vendor reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/e3842779547c83150569071d9980517cc9029fc0

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

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.