CVE-2025-21787Public exploit

Kernel service interruption via unterminated team option

Published Feb 27, 2025 · Updated May 12, 2026

Use of uninitialized data in Linux team networking allows local users to interrupt service via a crafted netlink team option. The team_nl_options_set_doit function accepted TEAM_OPTION_TYPE_STRING data by checking only its maximum length, then downstream mode handling treated the bytes as a terminated string and read beyond initialized input. Local low-privilege access to the generic netlink team interface is required; published scoring limits impact to availability.

CVSS severity5.5
Medium
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use of uninitialized data in Linux team networking allows local users to interrupt service via a crafted netlink team option. The team_nl_options_set_doit function accepted TEAM_OPTION_TYPE_STRING data by checking only its maximum length, then downstream mode handling treated the bytes as a terminated string and read beyond initialized input. Local low-privilege access to the generic netlink team interface is required; published scoring limits impact to availability.

The record

CVE
CVE-2025-21787
Published
Feb 27, 2025
Updated
May 12, 2026
Vendor
Siemens
Product
SIMATIC S7-1500 TM MFP - GNU/Linux subsystem
Classifications
CWE-908, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 27, 2025CVE publishedPublication date reported by the CVE source.
  2. May 12, 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=0 <*

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Siemens · SIMATIC S7-1500 TM MFP - GNU/Linux subsystemversion=0 <*
The Linux Kernel Organization · Linuxversion=3.3; version=3d249d4ca7d0ed6629a135ea1ea21c72286c0d80 <4236bf4716589558cc0f3c3612642b2c2141b04e; version=3d249d4ca7d0ed6629a135ea1ea21c72286c0d80 <4512482e4805dd30bc77dec511f2a2edba5cb868; version=3d249d4ca7d0ed6629a135ea1ea21c72286c0d80 <5bef3ac184b5626ea62385d6b82a1992b89d7940; version=3d249d4ca7d0ed6629a135ea1ea21c72286c0d80 <7c30483d0f6bdb2230e10e3e4be5167927eac7a0; version=3d249d4ca7d0ed6629a135ea1ea21c72286c0d80 <7f5af50f3aa0af8cbef9fb76fffeed69e8143f59; version=3d249d4ca7d0ed6629a135ea1ea21c72286c0d80 <8401cade1918281177974b32c925afdce750d292; version=3d249d4ca7d0ed6629a135ea1ea21c72286c0d80 <d071a91fa614ecdf760c29f61f6a7bfb7df796d6; version=3d249d4ca7d0ed6629a135ea1ea21c72286c0d80 <f443687ad20c70320d1248f35f57bf46cac8df0a

Published CVSS scores

5.5Amazon LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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.

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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 exploitPublished

Weakness, pattern, technique

CWE-908Use of Uninitialized Resource
T1499Endpoint Denial of Service

Public exploit references

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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