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CVE-2026-90049

Critical Vulnerability: CVE-2026-90049

In the Linux kernel, the following vulnerability has been resolved: net: skbuff: don't skb_tx_error() the source skb in skb_zerocopy() skb_zerocopy() copies frags from @from into @to. On an skb_orphan_frags() failure it calls skb_tx_error(@from), a destructive operation on the source skb the copy helper does not own. That completes @from's zerocopy uarg and clears SKBFL_ALL_ZEROCOPY, including the SKBFL_SHARED_FRAG page-ownership marker. Both callers already report the failure on their own dr

Wednesday, September 16, 2026Vulnios Threat Intelligence
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Vulnerability Snapshot

CVE-2026-90049 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.

Executive Summary

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

net: skbuff: don't skb_tx_error() the source skb in skb_zerocopy()

skb_zerocopy() copies frags from @from into @to. On an

skb_orphan_frags() failure it calls skb_tx_error(@from), a destructive

operation on the source skb the copy helper does not own. That completes

@from's zerocopy uarg and clears SKBFL_ALL_ZEROCOPY, including the

SKBFL_SHARED_FRAG page-ownership marker.

Both callers already report the failure on their own drop path.

nfnetlink_queue does it at nla_put_failure, and Open vSwitch does it in

the flow-miss drop arm of ovs_dp_process_packet(), so nothing is lost by

dropping it here.

On Open vSwitch's OVS_ACTION_ATTR_USERSPACE path the skb is not freed on

this error: do_execute_actions() ignores output_userspace()'s return

value and, unless the upcall was the last action, keeps forwarding the

same skb through the flow's remaining actions. The uarg is completed

while that skb is still in flight, telling th

Why It Matters

CVE-2026-90049 is rated CRITICAL severity, requiring immediate attention from security teams.

CVSS Base Score: 9.3/10

๐Ÿ›ก๏ธWhat Defenders Should Check

  • Check if you are affected โ€” Review your asset inventory for products listed in CVE-2026-90049.
  • 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-2026-90049 and similar vulnerabilities.

    References & Sources

    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

    Related Threat Alerts

    Frequently Asked Questions

    What is CVE-2026-90049?

    CVE-2026-90049 is a critical-severity vulnerability tracked under the Common Vulnerabilities and Exposures program. In the Linux kernel, the following vulnerability has been resolved:

    net: skbuff: don't skb_tx_error() the source skb in skb_zerocopy()

    skb_zerocopy() copies frags from @from into @to. On an

    skb_orph

    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-2026-90049. 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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