CVE-2025-39682 remediation guide

Linux Linux, SIMATIC CN 4100, linux kernel

In the Linux kernel, the following vulnerability has been resolved: tls: fix handling of zero-length records on the rx_list Each recvmsg() call must process either - only contiguous DATA records (any number of them) - one non-DATA record If the next record has different type than what has already been processed we break out of the main processing loop. If the record has already been decrypted (which may be the case for TLS 1.3 where we don't know type until decryption) we queue the pending record to the rx_list. Next recvmsg() will pick it up from there. Queuing the skb to rx_list after zer...

Open CVE record

ProductLinux Linux, SIMATIC CN 4100, linux kernel

Affected versions>= 84c61fe1a75b4255df1e1e7c054c9e6d048da417 < 2902c3ebcca52ca845c03182000e8d71d3a5196f, >= 84c61fe1a75b4255df1e1e7c054c9e6d048da417 < c09dd3773b5950e9cfb6c9b9a5f6e36d06c62677, >= 84c61fe1a75b4255df1e1e7c054c9e6d048da417 < 3439c15ae91a517cf3c650ea15a8987699416ad9, >= 84c61fe1a75b4255df1e1e7c054c9e6d048da417 < 29c0ce3c8cdb6dc5d61139c937f34cb888a6f42e, >= 84c61fe1a75b4255df1e1e7c054c9e6d048da417 < 62708b9452f8eb77513115b17c4f8d1a22ebf843, >= 6.0, < V5.0, >= 6.0 < 6.1.149, >= 6.2 < 6.6.103, >= 6.7 < 6.12.44, >= 6.13 < 6.16.4, 6.17, 11.0

Fixed versions6.1.149, 6.6.103, 6.12.44, 6.16.4

Priority basisReview · CVSS 7.1 · EPSS 0.47%

Identify the affected asset

Confirm whether Linux Linux, SIMATIC CN 4100, linux kernel is installed, record the deployed version and installation path, and identify exposed interfaces.

Record the product name, package or appliance identifier, and installed version.
Identify internet-facing, administrative, API, and internal access paths.
Preserve the pre-change configuration and relevant service logs.

Validate the affected-version match

Compare the deployed version with the affected range: >= 84c61fe1a75b4255df1e1e7c054c9e6d048da417 < 2902c3ebcca52ca845c03182000e8d71d3a5196f, >= 84c61fe1a75b4255df1e1e7c054c9e6d048da417 < c09dd3773b5950e9cfb6c9b9a5f6e36d06c62677, >= 84c61fe1a75b4255df1e1e7c054c9e6d048da417 < 3439c15ae91a517cf3c650ea15a8987699416ad9, >= 84c61fe1a75b4255df1e1e7c054c9e6d048da417 < 29c0ce3c8cdb6dc5d61139c937f34cb888a6f42e, >= 84c61fe1a75b4255df1e1e7c054c9e6d048da417 < 62708b9452f8eb77513115b17c4f8d1a22ebf843, >= 6.0, < V5.0, >= 6.0 < 6.1.149, >= 6.2 < 6.6.103, >= 6.7 < 6.12.44, >= 6.13 < 6.16.4, 6.17, 11.0. Treat incomplete inventory results as unresolved.

Prioritize with independent signals

The CVSS severity warrants an early asset and exposure review. Combine this signal with asset criticality, exposure, compensating controls, and business impact.

Apply supported remediation

Follow the vendor advisory or supported update path. Current fixed-version status: 6.1.149, 6.6.103, 6.12.44, 6.16.4. Preserve configuration and rollback material before change.

Verify the result

Confirm the resulting version, service health, authentication and access paths, monitoring coverage, and relevant security logs.

Confirm the expected version and package state.
Run a functional health check for critical service paths.
Review authentication, error, application, and security monitoring logs.
Reassess exposure if the supported fix cannot be applied.

Operational boundary

This page does not replace the vendor advisory, support contract, change-management process, or recovery plan. Do not infer that an asset is unaffected from an incomplete inventory query or a missing fixed-version field.