CVE-2025-38441

Kernel service interruption via undersized PPPoE packet

Published Jul 25, 2025 · Updated May 23, 2026

Use of uninitialized data in Linux netfilter flowtable allows local users to interrupt the system through a short PPPoE packet. The nf_flow_pppoe_proto() length check omits ETH_HLEN, then __nf_flow_pppoe_proto() reads the PPP protocol field beyond initialized packet data. Exploitation requires low-privileged local packet injection into a host with the netfilter flowtable PPPoE path active, and the documented impact is availability loss only.

CVSS severity5.5
Medium
EPSS probability0.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use of uninitialized data in Linux netfilter flowtable allows local users to interrupt the system through a short PPPoE packet. The nf_flow_pppoe_proto() length check omits ETH_HLEN, then __nf_flow_pppoe_proto() reads the PPP protocol field beyond initialized packet data. Exploitation requires low-privileged local packet injection into a host with the netfilter flowtable PPPoE path active, and the documented impact is availability loss only.

The record

CVE
CVE-2025-38441
Published
Jul 25, 2025
Updated
May 23, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-908, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 25, 2025CVE publishedPublication date reported by the CVE source.
  2. May 23, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.15.157 <5.15.189
  2. Affected versionversion=6.1.88 <6.1.146
  3. Affected versionversion=6.6.29 <6.6.99
  4. Affected versionversion=6.8.8 <6.9
  5. Affected versionversion=6.9
  6. Affected versionversion=87b3593bed1868b2d9fe096c01bcdf0ea86cbebf <18cdb3d982da8976b28d57691eb256ec5688fad2
  7. Affected versionversion=87b3593bed1868b2d9fe096c01bcdf0ea86cbebf <cfbf0665969af2c69d10c377d4c3d306e717efb4
  8. Affected versionversion=87b3593bed1868b2d9fe096c01bcdf0ea86cbebf <e0dd2e9729660f3f4fcb16e0aef87342911528ef
  9. Affected versionversion=8bf7c76a2a207ca2b4cfda0a279192adf27678d7 <eed8960b289327235185b7c32649c3470a3e969b
  10. Affected versionversion=a2471d271042ea18e8a6babc132a8716bb2f08b9 <9fbc49429a23b02595ba82536c5ea425fdabb221
  11. Affected versionversion=cf366ee3bc1b7d1c76a882640ba3b3f8f1039163
  12. Affected versionversion=d06977b9a4109f8738bb276125eb6a0b772bc433 <a3aea97d55964e70a1e6426aa4cafdc036e8a2dd

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.15.157 <5.15.189; version=6.1.88 <6.1.146; version=6.6.29 <6.6.99; version=6.8.8 <6.9; version=6.9; version=87b3593bed1868b2d9fe096c01bcdf0ea86cbebf <18cdb3d982da8976b28d57691eb256ec5688fad2; version=87b3593bed1868b2d9fe096c01bcdf0ea86cbebf <cfbf0665969af2c69d10c377d4c3d306e717efb4; version=87b3593bed1868b2d9fe096c01bcdf0ea86cbebf <e0dd2e9729660f3f4fcb16e0aef87342911528ef; version=8bf7c76a2a207ca2b4cfda0a279192adf27678d7 <eed8960b289327235185b7c32649c3470a3e969b; version=a2471d271042ea18e8a6babc132a8716bb2f08b9 <9fbc49429a23b02595ba82536c5ea425fdabb221; version=cf366ee3bc1b7d1c76a882640ba3b3f8f1039163; version=d06977b9a4109f8738bb276125eb6a0b772bc433 <a3aea97d55964e70a1e6426aa4cafdc036e8a2dd

Published CVSS scores

5.5Oracle LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-908Use of Uninitialized Resource
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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