CVE-2026-53003

Last refreshed2026-10-17

Status: UPDATED | Advisory ID: CVE-2026-53003

Key Details

CVE	CVE-2026-53003
CVSS Score / Version	7.5 (High) / CVSS v3.1
Updated	2026-10-16
CVSS Vector	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`
CVSS Prose	attack vector is network; attack complexity is low; privileges required is none; user interaction is none; scope is unchanged; confidentiality impact is none; integrity impact is none; availability impact is high.
Affected products	Linux Kernel

Vendor	Product	Affected Versions	Patch Status
Linux	Linux Kernel

Vendor

Product

Affected Versions

Patch Status

Linux

Linux Kernel

Subsystems	OT Supporting Infrastructure
Sectors	All Sectors

In the Linux kernel, the following vulnerability has been resolved:

pppoe: drop PFC frames

RFC 2516 Section 7 states that Protocol Field Compression (PFC) is NOT

RECOMMENDED for PPPoE. In practice, pppd does not support negotiating

PFC for PPPoE sessions, and the current PPPoE driver assumes an

uncompressed (2-byte) protocol field. However, the generic PPP layer

function ppp_input() is not aware of the negotiation result, and still

accepts PFC frames.

If a peer with a broken implementation or an attacker sends a frame with

a compressed (1-byte) protocol field, the subsequent PPP payload is

shifted by one byte. This causes the network header to be 4-byte

misaligned, which may trigger unaligned access exceptions on some

architectures.

To reduce the attack surface, drop PPPoE PFC frames. Introduce

ppp_skb_is_compressed_proto() helper function to be used in both

ppp_generic.c and pppoe.c to avoid open-coding. (NVD)

Monitor Linux's web page for any future patch releases.

Source	Reference
NVD	https://nvd.nist.gov/vuln/detail/CVE-2026-53003
CVE	https://www.cve.org/CVERecord?id=CVE-2026-53003

Source

Reference

NVD

CVE