dbcve.org
Linux KernelOperating system · Linux

CVE-2025-39805

MEDIUM · 5.5 CVSS v3.1 Published 2025-09-16
Fix available
A fix is available. Upgrade to 6.12.45 / 6.16.5 or later.
See remediation →
57/100
Remediation priority · Elevated
Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
In the Linux kernel, the following vulnerability has been resolved: net: macb: fix unregister_netdev call order in macb_remove() When removing a macb device, the driver calls phy_exit() before unregister_netdev(). This leads to a WARN from kernfs: ------------[ cut here ]------------ kernfs: can not remove 'attached_dev', no directory WARNING: CPU: 1 PID: 27146 at fs/kernfs/dir.c:1683 Call trace: kernfs_remove_by_name_ns+0xd8/0xf0 sysfs_remove_link+0x24/0x58 phy_detach+0x5c/0x168 phy_disconnect+0x4c/0x70 phylink_disconnect_phy+0x6c/0xc0 [phylink] macb_close+0x6c/0x170 [macb] ... macb_remove+0x60/0x168 [macb] platform_remove+0x5c/0x80 ... The warning happens because the PHY is being exited while the netdev is still registered. The correct order is to unregister the netdev before shutting down the PHY and cleaning up the MDIO bus. Fix this by moving unregister_netdev() ahead of phy_exit() in macb_remove().

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis

A detailed technical summary for this CVE is being prepared.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Linux KernelOperating system
Affected:>= 5.18, < 6.12.45>= 6.13, < 6.16.5= 6.17

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 6.12.45 / 6.16.5 or later
Fixed in 6.12.456.16.5
Vendor patch git.kernel.org →
Recommended fix High confidence

6.12.45 or 6.16.5 (depending on branch)

  1. Upgrade Linux kernel to version 6.12.45 or later if using the 6.12.x LTS branch
  2. Alternatively, upgrade to version 6.16.5 or later if using a newer kernel branch
  3. After upgrade, verify the macb driver module is loaded and network interface is functional using 'ip link show'
  4. Check dmesg for any remaining warnings related to macb or phy using 'dmesg | grep -i macb'
Caveat Kernel upgrades may require system reboot and could affect other kernel modules or drivers - test in staging environment first

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $1,600. Get the upgrade done

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2025-39805 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-39805 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data