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VulnerabilityPublished Updated

CVE-2026-80977: Linux kernel · net: skbuff: don't touch shared zerocopy state in skb_tx_error()

Affects Linux kernelSource GCVE Database

0

Not known to be exploited · CVSS 7.8 High.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 11 Sep 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Affected software

ProductAffectedFixed in
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threatsAffected
  • 6.17.0-5.5 – 7.0.0-34.34
22 affected builds
Fixed in–
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threatsAffected
  • 6.17.0-1002.2 – 7.0.0-1013.13
14 affected builds
Fixed in–
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threatsAffected
  • 6.17.0-1003.3 – 7.0.0-1014.14
14 affected builds
Fixed in–
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threatsAffected
  • 7.0.0-1003.3 – 7.0.0-1013.13
8 affected builds
Fixed in–
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threatsAffected
  • 6.17.0-1002.2 – 7.0.0-1013.13
12 affected builds
Fixed in–
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threatsAffected
  • 7.0.0-1002.3 – 7.0.0-1007.8
5 affected builds
Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A fix has been implemented in the Linux kernel to skip zerocopy state modifications for cloned skbs, preventing premature clearing of shared state. Users should apply the official kernel updates that include this fix. Since this is a kernel-level vulnerability, updating to the patched kernel version is the recommended remediation. Patch status is not explicitly stated in the provided data; users should consult the vendor or kernel mailing list advisories for the exact fixed versions.

Description

In the Linux kernel, the following vulnerability has been resolved: net: skbuff: don't touch shared zerocopy state in skb_tx_error() skb_tx_error() completes the zerocopy uarg and clears SKBFL_ALL_ZEROCOPY, and skb_zcopy_downgrade_managed() clears SKBFL_MANAGED_FRAG_REFS. Both live in skb_shinfo(), which every clone shares, while the caller only owns the reference it is about to drop. Through a clone it tells the producer its pages are free and drops SKBFL_SHARED_FRAG for an skb that is still in flight. Open vSwitch reaches this with a non-last OVS_ACTION_ATTR_RECIRC: clone_execute() sends a skb_clone() into ovs_dp_process_packet() while do_execute_actions() keeps forwarding the original, and skb_clone() does not privatise the frags here -- skb_orphan_frags() returns early on SKBFL_DONT_ORPHAN. A flow miss on the clone then strips the marker from the packet still being forwarded, and a later local ESP delivery decrypts in place over frags it does not own privately. Skip it for a cloned skb. Nothing is lost: skb_release_data() clears the zerocopy state once the last reference to the shared data goes.

References

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