SECUFOCUSNOW
Home›CVE index›CVE-2025-39871
Review reviewHigh

CVE-2025-39871

Linux Linux, SIMATIC S7-1500 CPU 1518-4 PN/DP MFP, SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP

In the Linux kernel, the following vulnerability has been resolved: dmaengine: idxd: Remove improper idxd_free The call to idxd_free() introduces a duplicate put_device() leading to a reference count underflow: refcount_t: underflow; use-after-free. WARNING: CPU: 15 PID: 4428 at lib/refcount.c:28 refcount_warn_saturate+0xbe/0x110 ... Call Trace: <TASK> idxd_remove+0xe4/0x120 [idxd] pci_device_remove+0x3f/0xb0 device_release_driver_internal+0x197/0x200 driver_detach+0x48/0x90 bus_remove_driver+0x74/0xf0 pci_unregister_driver+0x2e/0xb0 idxd_exit_module+0x34/0x7a0 [idxd] __do_sys_delete_module...

CVSS
7.8
EPSS
0.14%
3.83% percentile
CISA KEV
Not listed
Published
2025.09.23
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.14%
Technical severityCVSS 7.8

Vulnerability overview

In the Linux kernel, the following vulnerability has been resolved: dmaengine: idxd: Remove improper idxd_free The call to idxd_free() introduces a duplicate put_device() leading to a reference count underflow: refcount_t: underflow; use-after-free. WARNING: CPU: 15 PID: 4428 at lib/refcount.c:28 refcount_warn_saturate+0xbe/0x110 ... Call Trace: <TASK> idxd_remove+0xe4/0x120 [idxd] pci_device_remove+0x3f/0xb0 device_release_driver_internal+0x197/0x200 driver_detach+0x48/0x90 bus_remove_driver+0x74/0xf0 pci_unregister_driver+0x2e/0xb0 idxd_exit_module+0x34/0x7a0 [idxd] __do_sys_delete_module...

Affected product and versions

Product
Linux Linux, SIMATIC S7-1500 CPU 1518-4 PN/DP MFP, SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP
Affected versions
>= 68ac5a01f635b3791196fd1c39bc48497252c36f < 24414bbcb37e1af95190af36c21ae51d497e1a9e, >= d2d05fd0fc95c4defed6f7b87550e20e8baa1d97 < 0e95ee7f532b21206fe3f1c4054002b0d21e3b9c, >= 21f9f5cd9a0c75084d4369ba0b8c4f695c41dea7 < dd7a7e43269711d757fc260b0bbdf7138f75de11, >= d5449ff1b04dfe9ed8e455769aa01e4c2ccf6805 < da4fbc1488a4cec6748da685181ee4449a878dac, >= d5449ff1b04dfe9ed8e455769aa01e4c2ccf6805 < f41c538881eec4dcf5961a242097d447f848cda6, >= 2b7a961cea0e5b65afda911f76d14fec5c98d024, >= 6.1.140 < 6.1.160, >= 6.6.92 < 6.6.107, >= 6.12.30 < 6.12.48, >= 6.14.8 < 6.15, >= 6.15, >= V3.1.6, >= 6.1.140 < 6.2, >= 6.15.1 < 6.16.8, 6.15, 6.17
Fixed versions
6.2, 6.6.107, 6.12.48, 6.15, 6.16.8

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Linux Linux, SIMATIC S7-1500 CPU 1518-4 PN/DP MFP, SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE
CWE-416
CVE-2025-39871 — Linux Linux, SIMATIC S7-1500 CPU 1518-4 PN/DP MFP, SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP | SECUFOCUS NOW