PT-2026-38680 · Linux · Linux Kernel

Sandipan Roy

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Published

2026-05-08

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Updated

2026-05-09

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CVE-2026-43284

CVSS v3.1

7.8

High

VectorAV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)
Description Dirty Frag is a local privilege escalation issue in the Linux kernel networking functionality related to xfrm/IPsec ESP and RxRPC. The problem occurs because IPv4/IPv6 datagram append paths failed to set the SKBFL SHARED FRAG flag when splicing pages into UDP skbs. This allows an ESP-in-UDP packet made from shared pipe pages to be treated as an ordinary uncloned nonlinear skb. Consequently, the ESP input uses a fast path that decrypts data in place over memory not privately owned by the skb, leading to a page cache write error. A local unprivileged attacker can abuse these paths to modify page cache contents and escalate privileges to root.
Recommendations Update the kernel to a version containing the fix, such as version 6.18.28. As a temporary workaround, disable the esp4, esp6, and rxrpc kernel modules. Restrict the use of the kafs module as it depends on the vulnerable components.

Exploit

Fix

LPE

Use After Free

Weakness Enumeration

Related Identifiers

ALSA-2026:A004
ALSA-2026:A005
ALSA-2026:A006
ALSA-2026:A007
CVE-2026-43284
ECHO-C2C0-9DB5-201C

Affected Products

Linux Kernel