CVE-2025-39691 remediation guide

Linux Linux, SIMATIC CN 4100, SIMATIC S7-1500 CPU 1518-4 PN/DP MFP

In the Linux kernel, the following vulnerability has been resolved: fs/buffer: fix use-after-free when call bh_read() helper There's issue as follows: BUG: KASAN: stack-out-of-bounds in end_buffer_read_sync+0xe3/0x110 Read of size 8 at addr ffffc9000168f7f8 by task swapper/3/0 CPU: 3 UID: 0 PID: 0 Comm: swapper/3 Not tainted 6.16.0-862.14.0.6.x86_64 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) Call Trace: <IRQ> dump_stack_lvl+0x55/0x70 print_address_description.constprop.0+0x2c/0x390 print_report+0xb4/0x270 kasan_report+0xb8/0xf0 end_buffer_read_sync+0xe3/0x110 end_bio_bh_io_sync+0...

Open CVE record

ProductLinux Linux, SIMATIC CN 4100, SIMATIC S7-1500 CPU 1518-4 PN/DP MFP

Affected versions>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 70a09115da586bf662c3bae9c0c4a1b99251fad9, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 3169edb8945c295cf89120fc6b2c35cfe3ad4c9e, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 03b40bf5d0389ca23ae6857ee25789f0e0b47ce8, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < c58c6b532b7b69537cfd9ef701c7e37cdcf79dc4, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < c5aa6ba1127307ab5dc3773eaf40d73a3423841f, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 042cf48ecf67f72c8b3846c7fac678f472712ff3, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 90b5193edb323fefbee0e4e5bc39ed89dcc37719, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 7375f22495e7cd1c5b3b5af9dcc4f6dffe34ce49, >= 2.6.12, < V5.0, >= V3.1.6, >= 2.6.13 < 5.4.297, >= 5.5 < 5.10.241, >= 5.11 < 5.15.190, >= 5.16 < 6.1.149, >= 6.2 < 6.6.103, >= 6.7 < 6.12.44, >= 6.13 < 6.16.4, 2.6.12, 6.17

Fixed versions5.4.297, 5.10.241, 5.15.190, 6.1.149, 6.6.103, 6.12.44, 6.16.4

Priority basisReview · CVSS 7.8 · EPSS 0.16%

Identify the affected asset

Confirm whether Linux Linux, SIMATIC CN 4100, SIMATIC S7-1500 CPU 1518-4 PN/DP MFP 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: >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 70a09115da586bf662c3bae9c0c4a1b99251fad9, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 3169edb8945c295cf89120fc6b2c35cfe3ad4c9e, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 03b40bf5d0389ca23ae6857ee25789f0e0b47ce8, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < c58c6b532b7b69537cfd9ef701c7e37cdcf79dc4, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < c5aa6ba1127307ab5dc3773eaf40d73a3423841f, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 042cf48ecf67f72c8b3846c7fac678f472712ff3, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 90b5193edb323fefbee0e4e5bc39ed89dcc37719, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 7375f22495e7cd1c5b3b5af9dcc4f6dffe34ce49, >= 2.6.12, < V5.0, >= V3.1.6, >= 2.6.13 < 5.4.297, >= 5.5 < 5.10.241, >= 5.11 < 5.15.190, >= 5.16 < 6.1.149, >= 6.2 < 6.6.103, >= 6.7 < 6.12.44, >= 6.13 < 6.16.4, 2.6.12, 6.17. 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: 5.4.297, 5.10.241, 5.15.190, 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.