Local kernel compromise via freed flow dereference
Published Oct 15, 2025 · Updated Sep 8, 2026
Use-after-free in affected Linux kernels and Siemens MFP firmware 3.1.6 and later allows local users to corrupt kernel memory or crash the system. The otx2_tc_add_flow function queues new_node for RCU reclamation and then dereferences its rq and leaf_profile members on the error path. Reaching that path requires traffic-control access with CAP_NET_ADMIN on an OcteonTX2 PF, VF, or representor interface; reclaimed values can alter driver state, expose data, or interrupt service.
Summary
What happened
Use-after-free in affected Linux kernels and Siemens MFP firmware 3.1.6 and later allows local users to corrupt kernel memory or crash the system. The otx2_tc_add_flow function queues new_node for RCU reclamation and then dereferences its rq and leaf_profile members on the error path. Reaching that path requires traffic-control access with CAP_NET_ADMIN on an OcteonTX2 PF, VF, or representor interface; reclaimed values can alter driver state, expose data, or interrupt service.
The record
- CVE
- CVE-2025-39978
- Published
- Oct 15, 2025
- Updated
- Sep 8, 2026
- Vendor
- Siemens
- Product
- SIPLUS S7-1500 CPU 1518-4 PN/DP MFP
- Classifications
- CWE-825, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Oct 15, 2025CVE publishedPublication date reported by the CVE source.
- Sep 8, 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.
- Affected versionversion=V3.1.6 <*
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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