CVE-2026-31496

Cross-namespace disclosure via unfiltered proc expectations

Published Apr 22, 2026 · Updated Apr 22, 2026

Information disclosure in Linux Kernel releases from 2.6.28 allows local users to read connection expectations from other network namespaces. The nf_conntrack_expect proc iterator emits hash-table entries without checking that each expectation belongs to the reader's network namespace. A local proc read is required, and exposure is limited to connection-tracking expectation metadata from co-hosted namespaces.

CVSS severity5.5
Medium
EPSS probability0.12%
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 releases from 2.6.28 allows local users to read connection expectations from other network namespaces. The nf_conntrack_expect proc iterator emits hash-table entries without checking that each expectation belongs to the reader's network namespace. A local proc read is required, and exposure is limited to connection-tracking expectation metadata from co-hosted namespaces.

The record

CVE
CVE-2026-31496
Published
Apr 22, 2026
Updated
Apr 22, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1005
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 22, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 22, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=2.6.28
  2. Affected versionversion=9b03f38d0487f3908696242286d934c9b38f9d2a <168145c87444619e3e649322bbe7719ecd00d411
  3. Affected versionversion=9b03f38d0487f3908696242286d934c9b38f9d2a <2028405ea6987b4448784e439413202cfe19f43f
  4. Affected versionversion=9b03f38d0487f3908696242286d934c9b38f9d2a <3265ad619987cb551edaf797ed056d80ac450225
  5. Affected versionversion=9b03f38d0487f3908696242286d934c9b38f9d2a <3db5647984de03d9cae0dcddb509b058351f0ee4
  6. Affected versionversion=9b03f38d0487f3908696242286d934c9b38f9d2a <9ca8c7452493d915f9bbf2f39331e6c583d07a23
  7. Affected versionversion=9b03f38d0487f3908696242286d934c9b38f9d2a <dcfcd95b3ae7683e8ae55c92284b3430ce614bc7

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=2.6.28; version=9b03f38d0487f3908696242286d934c9b38f9d2a <168145c87444619e3e649322bbe7719ecd00d411; version=9b03f38d0487f3908696242286d934c9b38f9d2a <2028405ea6987b4448784e439413202cfe19f43f; version=9b03f38d0487f3908696242286d934c9b38f9d2a <3265ad619987cb551edaf797ed056d80ac450225; version=9b03f38d0487f3908696242286d934c9b38f9d2a <3db5647984de03d9cae0dcddb509b058351f0ee4; version=9b03f38d0487f3908696242286d934c9b38f9d2a <9ca8c7452493d915f9bbf2f39331e6c583d07a23; version=9b03f38d0487f3908696242286d934c9b38f9d2a <dcfcd95b3ae7683e8ae55c92284b3430ce614bc7

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 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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