CVE-2026-23057

Kernel-memory disclosure via nonlinear skb coalescing

Published Feb 4, 2026 · Updated Feb 4, 2026

Information disclosure in Linux Kernel allows local users to read uninitialized kernel memory through loopback vsock zerocopy. The virtio-vsock receive coalescer treats every short skb as linear and copies from a nonlinear zerocopy skb into tailroom of the preceding linear skb. Exploitation requires local low-privileged access and the loopback transport; the supported consequence is disclosure of kernel memory.

CVSS severity5.5
Medium
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in Linux Kernel allows local users to read uninitialized kernel memory through loopback vsock zerocopy. The virtio-vsock receive coalescer treats every short skb as linear and copies from a nonlinear zerocopy skb into tailroom of the preceding linear skb. Exploitation requires local low-privileged access and the loopback transport; the supported consequence is disclosure of kernel memory.

The record

CVE
CVE-2026-23057
Published
Feb 4, 2026
Updated
Feb 4, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1005
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 4, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 4, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=581512a6dc939ef122e49336626ae159f3b8a345 <0386bd321d0f95d041a7b3d7b07643411b044a96
  2. Affected versionversion=581512a6dc939ef122e49336626ae159f3b8a345 <568e9cd8ed7ca9bf748c7687ba6501f29d30e59f
  3. Affected versionversion=581512a6dc939ef122e49336626ae159f3b8a345 <63ef9b300bd09e24c57050c5dbe68feedce42e72
  4. Affected versionversion=6.7

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=581512a6dc939ef122e49336626ae159f3b8a345 <0386bd321d0f95d041a7b3d7b07643411b044a96; version=581512a6dc939ef122e49336626ae159f3b8a345 <568e9cd8ed7ca9bf748c7687ba6501f29d30e59f; version=581512a6dc939ef122e49336626ae159f3b8a345 <63ef9b300bd09e24c57050c5dbe68feedce42e72; version=6.7

Published CVSS scores

5.5Oracle LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
7.0Amazon LinuxCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1005Data from Local System

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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