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VulnerabilityPublished Updated

CVE-2025-39990: Linux kernel · bpf: Check the helper function is valid in get_helper_proto

Source GCVE Database

0
Authoritative record:CVE-2025-39990· High 7.8

Not known to be exploited · CVSS 7.8 High · fixed in e4414b01c1cd9887bbde92f946c1ba94e40d6d64 : patch Linux kernel soon.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 8% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in e4414b01c1cd9887bbde92f946c1ba94e40d6d64, dfbff47f120e4b0793ca0e0b8660361ccac25a74, 6233715b4b714068d6c831d214a4e8792109875a +1
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 15 Oct 2025

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade Linux kernel to e4414b01c1cd9887bbde92f946c1ba94e40d6d64, dfbff47f120e4b0793ca0e0b8660361ccac25a74, 6233715b4b714068d6c831d214a4e8792109875a or 3d429cb1278e995e22995ef117fa96d223a67e93.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ f470378c7562a2818b45ed11c98973f2b89eedd3, < e4414b01c1cd9887bbde92f946c1ba94e40d6d64
Fixed in
  • e4414b01c1cd9887bbde92f946c1ba94e40d6d64
LinuxLinuxAffected
  • ≥ f470378c7562a2818b45ed11c98973f2b89eedd3, < dfbff47f120e4b0793ca0e0b8660361ccac25a74
Fixed in
  • dfbff47f120e4b0793ca0e0b8660361ccac25a74
LinuxLinuxAffected
  • ≥ f470378c7562a2818b45ed11c98973f2b89eedd3, < 6233715b4b714068d6c831d214a4e8792109875a
Fixed in
  • 6233715b4b714068d6c831d214a4e8792109875a
LinuxLinuxAffected
  • ≥ f470378c7562a2818b45ed11c98973f2b89eedd3, < 3d429cb1278e995e22995ef117fa96d223a67e93
Fixed in
  • 3d429cb1278e995e22995ef117fa96d223a67e93
LinuxLinuxAffected
  • =5.8
Fixed in–

AI-suggested

A fix has been implemented in the Linux kernel to address this vulnerability by validating the helper function in get_helper_proto and marking the tail_call helper function as poisoned. Users should apply the official Linux kernel updates that include this fix. Patch status is not explicitly confirmed in the provided data; therefore, check the vendor advisory or Linux kernel mailing lists for the latest remediation guidance.

Description

A high severity vulnerability in the Linux kernel related to the BPF subsystem was resolved. The issue involved a verifier bug where a helper function pointer could be NULL due to a disabled configuration option. The fix involves validating the helper function directly in get_helper_proto and marking the tail_call helper function as poisoned since it is unused by design.

References

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