PatchSiren cyber security CVE debrief
CVE-2026-64056 Linux CVE debrief
CVE-2026-64056 is a Linux kernel vulnerability affecting the net: ethernet: cortina driver. The issue arises from a static local SKB used to assemble packets from fragments in gmac_rx(), which can lead to races between two ethernet ports on the Gemini device. To address this, the RX SKB should be made a per-port variable carried over between invocations in the port struct. The SKB pointer should be zeroed when napi_gro_frags() is called, on error, or if the port is stopped. This vulnerability has been resolved through patch review and application.
- Vendor
- Linux
- Product
- Unknown
- CVSS
- CRITICAL 9.8
- CISA KEV
- Not listed in stored evidence
- Original CVE published
- 2026-07-19
- Original CVE updated
- 2026-09-02
- Advisory published
- 2026-07-19
- Advisory updated
- 2026-09-02
Who should care
Linux kernel users and administrators, particularly those utilizing the cortina ethernet driver, should be aware of this vulnerability and take necessary precautions. Affected operators should review system deployments for the cortina driver and assess potential exposure. Vulnerability management and security teams should prioritize patching and monitor for potential issues related to packet assembly and ethernet port usage.
Technical summary
The Linux kernel vulnerability CVE-2026-64056 is related to the net: ethernet: cortina driver. The current implementation uses a static local SKB in gmac_rx() for packet assembly from fragments. However, since the Gemini device has two ethernet ports, this can lead to potential races if both ports are in use. The proposed fix involves making the RX SKB a per-port variable stored in the port struct and ensuring the SKB pointer is properly zeroed under certain conditions. Linux kernel users should review and apply patches to mitigate this vulnerability.
Defensive priority
Medium
Recommended defensive actions
- Review and apply the provided kernel patches to address the vulnerability
- Inventory Linux systems using the cortina ethernet driver
- Monitor for potential issues related to packet assembly and ethernet port usage
- 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
Evidence notes
The CVE record and associated details were obtained from the official CVE and NVD sources. The vulnerability was resolved through patch review and application. Linux kernel users should verify their systems for the cortina ethernet driver and review the official advisory for patching guidance. Evidence is limited to public CVE and NVD records, with no additional source details available for verification.
Sources and references
Verified primary and authoritative sources
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CVE-2026-64056 CVE Program record
Publisher, destination, and source semantics verified
URL: https://www.cve.org/CVERecord?id=CVE-2026-64056
CVE Program - Official CVE Program record with source-provided CVE metadata.
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CVE-2026-64056 NVD vulnerability detail
Publisher, destination, and source semantics verified
URL: https://nvd.nist.gov/vuln/detail/CVE-2026-64056
NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.
Supplemental references
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Source reference
Unverified legacy reference
URL: https://git.kernel.org/stable/c/06937db21ee311ed07eba47954447245041a982d
416baaa9-dc9f-4396-8d5f-8c081fb06d67
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Source reference
Unverified legacy reference
URL: https://git.kernel.org/stable/c/27856d533eca3804008695f61c1e4d5ff984196b
416baaa9-dc9f-4396-8d5f-8c081fb06d67
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Source reference
Unverified legacy reference
URL: https://git.kernel.org/stable/c/3b249988d774dacf13b203817e971934a42243c4
416baaa9-dc9f-4396-8d5f-8c081fb06d67
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Source reference
Unverified legacy reference
URL: https://git.kernel.org/stable/c/67a35e7da7ef9d2f000aa758552a128324c604a0
416baaa9-dc9f-4396-8d5f-8c081fb06d67
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Source reference
Unverified legacy reference
URL: https://git.kernel.org/stable/c/6bba24e9ebe6f1c0b356cd471e36bdc7fa434897
416baaa9-dc9f-4396-8d5f-8c081fb06d67
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Source reference
Unverified legacy reference
URL: https://git.kernel.org/stable/c/72158ea185b27afae163949b0e86164cb6b64e55
416baaa9-dc9f-4396-8d5f-8c081fb06d67
-
Source reference
Unverified legacy reference
URL: https://git.kernel.org/stable/c/b6b22824b30e48ce1df3a2e80990f4b8505deb50
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.