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Vulnerabilities

Vulnerability · CVE-2025-39901

In the Linux kernel, the following vulnerability has been resolved: i40e: remove read access to debugfs files The 'command' and 'netdev_ops' debugfs files are a legacy debugging in

Published Oct 1, 2025 · catalog updated Oct 14, 2026 · In the Linux kernel,

Check if you run it

No confirmed exploitation is on record for CVE-2025-39901. EPSS is 0.15%. Act only if a listed version of In the Linux kernel, is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (In the Linux kernel,).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
High7.1
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.15%
Remediation
Advisory link
Affected products
Ubuntu:16.04:LTS linux-hwe-edge · Ubuntu:Pro:14.04:LTS linux · Ubuntu:Pro:14.04:LTS linux-aws · Ubuntu:Pro:14.04:LTS linux-azure · Ubuntu:Pro:14.04:LTS linux-lts-xenial · Ubuntu:Pro:16.04:LTS linux

In the Linux kernel, the following vulnerability has been resolved: i40e: remove read access to debugfs files The 'command' and 'netdev_ops' debugfs files are a legacy debugging interface supported by the i40e driver since its early days by commit 02e9c290814c ("i40e: debugfs interface"). Both of these debugfs files provide a read handler which is mostly useless, and which is implemented with questionable logic. They both use a static 256 byte buffer which is initialized to the empty string. In the case of the 'command' file this buffer is literally never used and simply wastes space. In the case of the 'netdev_ops' file, the last command written is saved here. On read, the files contents are presented as the name of the device followed by a colon and then the contents of their respective static buffer. For 'command' this will always be " : ". For 'netdev_ops', this will be " : ". But note the buffer is shared between all devices operated by this module. At best, it is mostly meaningless information, and at worse it could be accessed simultaneously as there doesn't appear to be any locking mechanism. We have also recently received multiple reports for both read functions about their use of snprintf and potential overflow that could result in reading arbitrary kernel memory. For the 'command' file, this is definitely impossible, since the static buffer is always zero and never written to. For the 'netdev_ops' file, it does appear to be possible, if the user carefully crafts the command input, it will be copied into the buffer, which could be large enough to cause snprintf to truncate, which then causes the copy_to_user to read beyond the length of the buffer allocated by kzalloc. A minimal fix would be to replace snprintf() with scnprintf() which would cap the return to the number of bytes written, preventing an overflow. A more involved fix would be to drop the mostly useless static buffers, saving 512 bytes and modifying the read functions to stop needing those as

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • Ubuntu:16.04:LTS linux-hwe-edge4.8.0-28.30~16.04.1, 4.8.0-30.32~16.04.1, 4.8.0-32.34~16.04.1
  • Ubuntu:Pro:14.04:LTS linux3.11.0-12.19, 3.12.0-1.3, 3.12.0-2.5
  • Ubuntu:Pro:14.04:LTS linux-aws4.4.0-1002.2, 4.4.0-1003.3, 4.4.0-1005.5
  • Ubuntu:Pro:14.04:LTS linux-azure4.15.0-1023.24~14.04.1, 4.15.0-1030.31~14.04.1, 4.15.0-1031.32~14.04.1
  • Ubuntu:Pro:14.04:LTS linux-lts-xenial4.4.0-13.29~14.04.1, 4.4.0-14.30~14.04.2, 4.4.0-15.31~14.04.1
  • Ubuntu:Pro:16.04:LTS linux4.2.0-16.19, 4.2.0-17.21, 4.2.0-19.23
  • Ubuntu:Pro:16.04:LTS linux-aws4.4.0-1001.10, 4.4.0-1003.12, 4.4.0-1004.13
  • Ubuntu:Pro:16.04:LTS linux-aws-hwe4.15.0-1030.31~16.04.1, 4.15.0-1031.33~16.04.1, 4.15.0-1032.34~16.04.1
  • Ubuntu:Pro:16.04:LTS linux-azure4.11.0-1009.9, 4.11.0-1011.11, 4.11.0-1013.13
  • Ubuntu:Pro:16.04:LTS linux-gcp4.10.0-1004.4, 4.10.0-1006.6, 4.10.0-1007.7
  • Ubuntu:Pro:16.04:LTS linux-hwe4.8.0-36.36~16.04.1, 4.8.0-39.42~16.04.1, 4.8.0-41.44~16.04.1
  • Ubuntu:Pro:16.04:LTS linux-kvm4.4.0-1004.9, 4.4.0-1007.12, 4.4.0-1008.13

How to fix CVE-2025-39901

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2025-39901. EPSS is 0.15%. Act only if a listed version of In the Linux kernel, is installed.

Which versions are affected?

Compare what you have installed with 4.8.0-28.30~16.04.1, 4.8.0-30.32~16.04.1, 4.8.0-32.34~16.04.1, 3.11.0-12.19, 3.12.0-1.3, 3.12.0-2.5, 4.4.0-1002.2, 4.4.0-1003.3, 4.4.0-1005.5, 4.15.0-1023.24~14.04.1, 4.15.0-1030.31~14.04.1, 4.15.0-1031.32~14.04.1, 4.4.0-13.29~14.04.1, 4.4.0-14.30~14.04.2, 4.4.0-15.31~14.04.1, 4.2.0-16.19, 4.2.0-17.21, 4.2.0-19.23. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 0.15%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Technology hubs

Ubuntu security

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 1, 2025 · OpenSSF OSV / OSV Scanner

    Detected

    In the Linux kernel, the following vulnerability has been resolved: i40e: remove read access to debugfs files The 'command' and 'netdev_ops' debugfs files are a legacy debugging interface supported by the i40e driver since its early days by commit 02e9c290814c ("i40e: debugfs interface"). Both of these debugfs files provide a read handler which is mostly useless, and which is implemented with ques

  2. Oct 14, 2026 · OpenSSF OSV / OSV Scanner

    Fix available

    linux-aws-6.8 fixed in 6.8.0-1050.53~22.04.1; linux-azure-6.8 fixed in 6.8.0-1051.57~22.04.1; linux-azure-fde-6.8 fixed in 6.8.0-1058.65~22.04.1; linux-gcp-6.8 fixed in 6.8.0-1052.55~22.04.1

  3. Oct 14, 2026 · OpenSSF OSV / OSV Scanner

    Updated

    In the Linux kernel, the following vulnerability has been resolved: i40e: remove read access to debugfs files The 'command' and 'netdev_ops' debugfs files are a legacy debugging interface supported by the i40e driver since its early days by commit 02e9c290814c ("i40e: debugfs interface"). Both of these debugfs files provide a read handler which is mostly useless, and which is implemented with ques

Sources

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.