CVE-2026-53003Network attack vector

Denial of service via compressed PPPoE protocol fields

Published Jun 24, 2026 · Updated Jun 24, 2026

Denial of service in the Linux Kernel PPPoE driver allows remote attackers to trigger unaligned access exceptions via PFC frames. ppp_input() accepts a one-byte compressed protocol field despite the driver assuming two bytes, shifting the PPP payload and misaligning the network header. The gate is a malicious PPPoE peer and a strict-alignment architecture; the resulting unaligned exception causes denial of service or system instability.

CVSS severity7.5
High
EPSS probability0.50%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Denial of service in the Linux Kernel PPPoE driver allows remote attackers to trigger unaligned access exceptions via PFC frames. ppp_input() accepts a one-byte compressed protocol field despite the driver assuming two bytes, shifting the PPP payload and misaligning the network header. The gate is a malicious PPPoE peer and a strict-alignment architecture; the resulting unaligned exception causes denial of service or system instability.

The record

CVE
CVE-2026-53003
Published
Jun 24, 2026
Updated
Jun 24, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-1102, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 24, 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=5.0
  2. Affected versionversion=7fb1b8ca8fa1ee34ffc328f17f78da68c7cc04e6 <0cab5d077dd1efd2bd1a47271acc35894f945b4f
  3. Affected versionversion=7fb1b8ca8fa1ee34ffc328f17f78da68c7cc04e6 <2b5c3c040d020e3ab3b9a8887031202d96843b1e
  4. Affected versionversion=7fb1b8ca8fa1ee34ffc328f17f78da68c7cc04e6 <49e41b60ccd1bdbe9e218420f716dd5f9a2f9c71
  5. Affected versionversion=7fb1b8ca8fa1ee34ffc328f17f78da68c7cc04e6 <8a5e840babc5c0fbd10c73728a13192347771ec6
  6. Affected versionversion=7fb1b8ca8fa1ee34ffc328f17f78da68c7cc04e6 <ba758fdf1399f310b30098b6faa3fd043de47dd2
  7. Affected versionversion=7fb1b8ca8fa1ee34ffc328f17f78da68c7cc04e6 <cb3beef35ab5e0c1afca9fd7648c6ae499786377
  8. Affected versionversion=7fb1b8ca8fa1ee34ffc328f17f78da68c7cc04e6 <cc1ff87bce1ccd38410ab10960f576dcd17db679
  9. Affected versionversion=7fb1b8ca8fa1ee34ffc328f17f78da68c7cc04e6 <fcca1df05322bb04e344dd1178b54b76a08eb7c3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=5.0; version=7fb1b8ca8fa1ee34ffc328f17f78da68c7cc04e6 <0cab5d077dd1efd2bd1a47271acc35894f945b4f; version=7fb1b8ca8fa1ee34ffc328f17f78da68c7cc04e6 <2b5c3c040d020e3ab3b9a8887031202d96843b1e; version=7fb1b8ca8fa1ee34ffc328f17f78da68c7cc04e6 <49e41b60ccd1bdbe9e218420f716dd5f9a2f9c71; version=7fb1b8ca8fa1ee34ffc328f17f78da68c7cc04e6 <8a5e840babc5c0fbd10c73728a13192347771ec6; version=7fb1b8ca8fa1ee34ffc328f17f78da68c7cc04e6 <ba758fdf1399f310b30098b6faa3fd043de47dd2; version=7fb1b8ca8fa1ee34ffc328f17f78da68c7cc04e6 <cb3beef35ab5e0c1afca9fd7648c6ae499786377; version=7fb1b8ca8fa1ee34ffc328f17f78da68c7cc04e6 <cc1ff87bce1ccd38410ab10960f576dcd17db679; version=7fb1b8ca8fa1ee34ffc328f17f78da68c7cc04e6 <fcca1df05322bb04e344dd1178b54b76a08eb7c3

Published CVSS scores

6.5Amazon LinuxCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5LinuxCVSS:3.1/AV:N/AC:L/PR:N/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

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

Weakness, pattern, technique

CWE-1102Reliance on Machine-Dependent Data Representation
T1499.004Endpoint Denial of Service: Application 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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo