CVE-2025-21848

Kernel crash via unchecked NFP message allocation

Published Mar 12, 2025 · Updated Jul 14, 2026

NULL pointer dereference in Linux kernel NFP BPF support from 4.16 allows local users with elevated capabilities to crash the kernel. nfp_bpf_cmsg_alloc() dereferences the result of nfp_app_ctrl_msg_alloc() without first checking whether allocation returned NULL. Reachability requires an NFP device and CAP_BPF or CAP_SYS_ADMIN; the documented consequence is an availability-only kernel crash.

CVSS severity5.5
Medium
EPSS probability0.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

NULL pointer dereference in Linux kernel NFP BPF support from 4.16 allows local users with elevated capabilities to crash the kernel. nfp_bpf_cmsg_alloc() dereferences the result of nfp_app_ctrl_msg_alloc() without first checking whether allocation returned NULL. Reachability requires an NFP device and CAP_BPF or CAP_SYS_ADMIN; the documented consequence is an availability-only kernel crash.

The record

CVE
CVE-2025-21848
Published
Mar 12, 2025
Updated
Jul 14, 2026
Vendor
Siemens
Product
SIPLUS S7-1500 CPU 1518-4 PN/DP MFP
Classifications
CWE-476, T1499.004
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Mar 12, 2025CVE publishedPublication date reported by the CVE source.
  2. Jul 14, 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=V3.1.5 <*

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Siemens · SIPLUS S7-1500 CPU 1518-4 PN/DP MFPversion=V3.1.5 <*
The Linux Kernel Organization · Linuxversion=4.16; version=ff3d43f7568c82b335d7df2d40a31447c3fce10c <1358d8e07afdf21d49ca6f00c56048442977e00a; version=ff3d43f7568c82b335d7df2d40a31447c3fce10c <29ccb1e4040da6ff02b7e64efaa2f8e6bf06020d; version=ff3d43f7568c82b335d7df2d40a31447c3fce10c <878e7b11736e062514e58f3b445ff343e6705537; version=ff3d43f7568c82b335d7df2d40a31447c3fce10c <897c32cd763fd11d0b6ed024c52f44d2475bb820; version=ff3d43f7568c82b335d7df2d40a31447c3fce10c <924b239f9704566e0d86abd894d2d64bd73c11eb; version=ff3d43f7568c82b335d7df2d40a31447c3fce10c <bd97f60750bb581f07051f98e31dfda59d3a783b; version=ff3d43f7568c82b335d7df2d40a31447c3fce10c <d64c6ca420019712e194fe095b55f87363e22a9a; version=ff3d43f7568c82b335d7df2d40a31447c3fce10c <e976ea6c5e1b005c64467cbf94a8577aae9c7d81
Siemens · SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPversion=V3.1.5 <*
Siemens · SIMATIC S7-1500 CPU 1518-4 PN/DP MFPversion=V3.1.5 <*

Published CVSS scores

5.5SiemensCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5CISA ADPCVSS: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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499.004Application or System Exploitation

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo