CVE-2025-21659

Cross-namespace NAPI access via global ID lookup

Published Jan 21, 2025 · Updated Aug 5, 2026

Network namespace isolation failure in Linux 6.8 through 6.12.9 allows local users to access another namespace's NAPI instances. The netdev_nl_napi_get_doit handler passed a user-supplied NAPI ID to the global napi_by_id lookup without checking the owning device's network namespace. Reaching the operation requires high local privileges, and cross-namespace access can expose NAPI data or alter per-NAPI configuration outside the caller's namespace.

CVSS severity8.1
High
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Network namespace isolation failure in Linux 6.8 through 6.12.9 allows local users to access another namespace's NAPI instances. The netdev_nl_napi_get_doit handler passed a user-supplied NAPI ID to the global napi_by_id lookup without checking the owning device's network namespace. Reaching the operation requires high local privileges, and cross-namespace access can expose NAPI data or alter per-NAPI configuration outside the caller's namespace.

The record

CVE
CVE-2025-21659
Published
Jan 21, 2025
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Jan 21, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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=27f91aaf49b3a50e5a02ad5fa27b7c453d029a72 <b683ba0df11ff563cc237eb1b74d6adfa77226bf
  2. Affected versionversion=27f91aaf49b3a50e5a02ad5fa27b7c453d029a72 <d1cacd74776895f6435941f86a1130e58f6dd226
  3. Affected versionversion=6.8

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linuxversion=27f91aaf49b3a50e5a02ad5fa27b7c453d029a72 <b683ba0df11ff563cc237eb1b74d6adfa77226bf; version=27f91aaf49b3a50e5a02ad5fa27b7c453d029a72 <d1cacd74776895f6435941f86a1130e58f6dd226; version=6.8

Published CVSS scores

8.1kernel.orgCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:L/I:H/A:H
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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

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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