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CVE-2026-43465

Critical Vulnerability: CVE-2026-43465

In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: RX, Fix XDP multi-buf frag counting for striding RQ XDP multi-buf programs can modify the layout of the XDP buffer when the program calls bpf_xdp_pull_data() or bpf_xdp_adjust_tail(). The referenced commit in the fixes tag corrected the assumption in the mlx5 driver that the XDP buffer layout doesn't change during a program execution. However, this fix introduced another issue: the dropped fragments still need to be

Wednesday, May 13, 2026Vulnios Threat Intelligence
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Vulnerability Snapshot

CVE-2026-43465 is rated CRITICAL — exploitation is trivial or already observed in the wild and impact is severe. Patch immediately, not on the next maintenance window.

Executive Summary

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

net/mlx5e: RX, Fix XDP multi-buf frag counting for striding RQ

XDP multi-buf programs can modify the layout of the XDP buffer when the

program calls bpf_xdp_pull_data() or bpf_xdp_adjust_tail(). The

referenced commit in the fixes tag corrected the assumption in the mlx5

driver that the XDP buffer layout doesn't change during a program

execution. However, this fix introduced another issue: the dropped

fragments still need to be counted on the driver side to avoid page

fragment reference counting issues.

The issue was discovered by the drivers/net/xdp.py selftest,

more specifically the test_xdp_native_tx_mb:

  • The mlx5 driver allocates a page_pool page and initializes it with

    • a frag counter of 64 (pp_ref_count=64) and the internal frag counter

    to 0.

  • The test sends one packet with no payload.
  • On RX (mlx5e_skb_from_cqe_mpwrq_nonlinear()), mlx5 configures the XDP

    • buffer with the packet data starting in the firs

    Why It Matters

    CVE-2026-43465 is rated CRITICAL severity, requiring immediate attention from security teams.

    CVSS Base Score: 9.8/10

    🛡️What Defenders Should Check

  • Check if you are affected — Review your asset inventory for products listed in CVE-2026-43465.
  • Apply available patches — Visit vendor advisories for the latest security updates.
  • Monitor for exploitation — Check your SIEM/IDS logs for related indicators.

    • Use Vulnios to continuously monitor your exposure to CVE-2026-43465 and similar vulnerabilities.

    References & Sources

  • https://git.kernel.org/stable/c/043bd62f748bc9fd98154037aa598cffbd3c667c
  • https://git.kernel.org/stable/c/7d7342a18fadcdb70a63b3c930dc63528ce51832
  • https://git.kernel.org/stable/c/db25c42c2e1f9c0d136420fff5e5700f7e771a6f

    • How Vulnios Detects This

    Vulnios scans for this vulnerability using Trivy and Grype for SBOM-based CVE matching and Vulnios CVE feed continuous monitoring against your asset inventory. 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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    Sources

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    Frequently Asked Questions

    What is CVE-2026-43465?

    CVE-2026-43465 is a critical-severity vulnerability tracked under the Common Vulnerabilities and Exposures program. In the Linux kernel, the following vulnerability has been resolved:

    net/mlx5e: RX, Fix XDP multi-buf frag counting for striding RQ

    XDP multi-buf programs can modify the layout of the XDP buffer when

    Am I affected?

    Affected technology is listed in the Affected Products section above. If your asset inventory contains any of them, assume in-scope until you can prove otherwise.

    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-2026-43465. 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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