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CVE-2026-43039

Critical Vulnerability: CVE-2026-43039 โ€” linux โ€” linux_kernel

In the Linux kernel, the following vulnerability has been resolved: net: ti: icssg-prueth: fix missing data copy and wrong recycle in ZC RX dispatch emac_dispatch_skb_zc() allocates a new skb via napi_alloc_skb() but never copies the packet data from the XDP buffer into it. The skb is passed up the stack containing uninitialized heap memory instead of the actual received packet, leaking kernel heap contents to userspace. Copy the received packet data from the XDP buffer into the skb using skb

Thursday, May 14, 2026linuxVulnios Threat Intelligence
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Vulnerability Snapshot

CVE-2026-43039 is rated CRITICAL โ€” exploitation is trivial or already observed in the wild and impact is severe. Patch immediately, not on the next maintenance window.

Affected technology: linux_kernel.

Executive Summary

In the Linux kernel, the following vulnerability has been resolved:

net: ti: icssg-prueth: fix missing data copy and wrong recycle in ZC RX dispatch

emac_dispatch_skb_zc() allocates a new skb via napi_alloc_skb() but

never copies the packet data from the XDP buffer into it. The skb is

passed up the stack containing uninitialized heap memory instead of

the actual received packet, leaking kernel heap contents to userspace.

Copy the received packet data from the XDP buffer into the skb using

skb_copy_to_linear_data().

Additionally, remove the skb_mark_for_recycle() call since the skb is

backed by the NAPI page frag allocator, not page_pool. Marking a

non-page_pool skb for recycle causes the free path to return pages to

a page_pool that does not own them, corrupting page_pool state.

The non-ZC path (emac_rx_packet) does not have these issues because it

uses napi_build_skb() to wrap the existing page_pool page directly,

requiring no copy, and correctly marks for recycle since the page

Why It Matters

CVE-2026-43039 is rated CRITICAL severity, requiring immediate attention from security teams.

CVSS Base Score: 9.8/10

Affected Technologies

Vendors: linux

Products: linux_kernel

๐Ÿ›ก๏ธWhat Defenders Should Check

  • Check if you are affected โ€” Review your asset inventory for products listed in CVE-2026-43039.
  • Apply available patches โ€” Visit vendor advisories for the latest security updates.
  • Monitor for exploitation โ€” Check your SIEM/IDS logs for related indicators.
  • Use Vulnios to continuously monitor your exposure to CVE-2026-43039 and similar vulnerabilities.

    References & Sources

    How Vulnios Detects This

    Vulnios scans for this vulnerability using Trivy and Grype for CVE matching against your container images and OS package manifests. Run a scan against your environment to see whether you are exposed; findings are linked back to the original CVE record so triage starts with the patch path already known.

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    Affected Products

    linux_kernel

    Sources

    Related Threat Alerts

    Frequently Asked Questions

    What is CVE-2026-43039?

    CVE-2026-43039 is a critical-severity vulnerability tracked under the Common Vulnerabilities and Exposures program. In the Linux kernel, the following vulnerability has been resolved:

    net: ti: icssg-prueth: fix missing data copy and wrong recycle in ZC RX dispatch

    emac_dispatch_skb_zc() allocates a new skb via na

    Am I affected?

    Check whether your environment runs linux_kernel. If you operate any of those, treat yourself as in scope until you have evidence otherwise. A Vulnios scan will identify the exact assets carrying the affected version.

    How urgent is the response?

    Critical: do not wait for your normal patch cycle. Verify exposure today, apply the vendor patch immediately, and add detection rules for any post-exploit indicators.

    How do I remediate?

    Apply the vendor patch listed in the upstream advisory linked under Sources. If the patch is not yet available, follow the vendor-supplied workaround (often a config flag or feature disable) and add detections for the published exploit pattern in your SIEM. Re-scan after the patch lands to confirm the finding clears.

    Where can I track exploitation activity?

    Watch CISA's Known Exploited Vulnerabilities catalog for CVE-2026-43039. Cross-reference with public exploit databases and your own SIEM/IDS for indicator-of-compromise patterns. Vulnios tracks KEV status automatically and surfaces it on the asset findings view.

    How does Vulnios help with this?

    Vulnios continuously cross-references your asset inventory against the live CVE feed (NVD, vendor advisories, CISA KEV, and curated OSINT). When a new CVE matches your environment, you get a prioritized finding with the severity, KEV status, exploit-prediction (EPSS), and a direct path to the vendor patch. You can start a free scan from the homepage.

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