Skip to main content
VulnerabilityPublished Updated

CVE-2026-23057: Linux kernel · vsock/virtio: Coalesce only linear skb

Affects Linux kernelSource GCVE Database

0

Not known to be exploited · fixed in 6.8.0-1057.60~22.04.1 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 10:12 UTC

Severity
Medium

Rated by Threat Radar · No CVSS score from NVD or the CNA

EPSS
0.1% chance of exploitation in 30 days – higher than 9% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 6.8.0-1057.60~22.04.1, 6.8.0-1059.65~22.04.1, 6.8.0-1060.63~22.04.1 +27

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 4 Feb 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

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
Ubuntu 25.10linuxpkg:deb/ubuntu/linux@6.17.0-40.40?arch=source&distro=questingOther threatsAffected
  • 6.14.0-15.15 – 6.17.0-40.40
20 affected builds
Fixed in–
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws@6.17.0-1019.19?arch=source&distro=questingOther threatsAffected
  • 6.14.0-1005.5 – 6.17.0-1019.19
17 affected builds
Fixed in–
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure@6.17.0-1020.20?arch=source&distro=questingOther threatsAffected
  • 6.14.0-1004.4 – 6.17.0-1020.20
16 affected builds
Fixed in–
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde@6.17.0-1017.17?arch=source&distro=questingOther threatsAffected
  • 6.17.0-1003.3 – 6.17.0-1017.17
10 affected builds
Fixed in–
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp@6.17.0-1020.22?arch=source&distro=questingOther threatsAffected
  • 6.14.0-1006.6 – 6.17.0-1020.22
17 affected builds
Fixed in–
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle@6.17.0-1018.18?arch=source&distro=questingOther threatsAffected
  • 6.14.0-1005.5 – 6.17.0-1018.18
16 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 patch is available and should be applied to affected Linux kernel versions to ensure only linear skbs are coalesced in the vsock/virtio subsystem. The vendor advisory from Ubuntu confirms that this issue is fixed in updated kernel packages. Users should update their Linux kernel to the fixed versions as provided by their distribution.

Description

A vulnerability in the Linux kernel's vsock/virtio subsystem was resolved, involving improper coalescing of socket buffers (skbs) in the receive queue. The flaw occurs when a linear skb with spare tail room is followed by a small skb, and the kernel attempts to join them. Due to the introduction of MSG_ZEROCOPY support, the assumption that the small skb is always linear is incorrect, leading to data loss and appending uninitialized kernel memory to the linear skb. This issue affects only the loopback transport among the three virtio-based transports. A patch is available to ensure only linear skbs are coalesced.

References

Community reviews

Loading reviews…