Review reviewHigh

CVE-2025-39978

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: octeontx2-pf: Fix potential use after free in otx2_tc_add_flow() This code calls kfree_rcu(new_node, rcu) and then dereferences "new_node" and then dereferences it on the next line. Two lines later, we take a mutex so I don't think this is an RCU safe region. Re-order it to do the dereferences before queuing up the free.

CVSS
7.8
EPSS
0.14%
3.83% percentile
CISA KEV
Not listed
Published
2025.10.15
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: octeontx2-pf: Fix potential use after free in otx2_tc_add_flow() This code calls kfree_rcu(new_node, rcu) and then dereferences "new_node" and then dereferences it on the next line. Two lines later, we take a mutex so I don't think this is an RCU safe region. Re-order it to do the dereferences before queuing up the free.

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
>= 68fbff68dbea35f9e6f7649dd22fce492a5aedac < 5723120423a753a220b8b2954b273838b9d7e74a, >= 68fbff68dbea35f9e6f7649dd22fce492a5aedac < df2c071061ed52d2225d97b212d27ecedf456b8a, >= 68fbff68dbea35f9e6f7649dd22fce492a5aedac < c41b2941a024d4ec7c768e16ffb10a74b188fced, >= 68fbff68dbea35f9e6f7649dd22fce492a5aedac < a8a63f27c3a8a3714210d32b12fd0f16d0337414, >= 68fbff68dbea35f9e6f7649dd22fce492a5aedac < d9c70e93ec5988ab07ad2a92d9f9d12867f02c56, >= 5.14, >= V3.1.6
Fixed versions
No verified fixed-version field is available yet

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
Not available
CVE-2025-39978 — Linux Linux, SIMATIC S7-1500 CPU 1518-4 PN/DP MFP, SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP | SECUFOCUS NOW