Alibaba Cloud Linux 3 : 0001: kernel-hotfix (ALINUX3-HOTFIX-SA-2026:0001)

high Nessus Plugin ID 314422

Synopsis

The remote Alibaba Cloud Linux host is missing one or more security updates.

Description

The remote Alibaba Cloud Linux 3 host has packages installed that are affected by a vulnerability as referenced in the ALINUX3-HOTFIX-SA-2026:0001 advisory.

Package updates are available for Alibaba Cloud Linux 3 that fix the following vulnerabilities:

CVE-2026-43284:
In the Linux kernel, the following vulnerability has been resolved:
xfrm: esp: avoid in-place decrypt on shared skb frags MSG_SPLICE_PAGES can attach pages from a pipe directly to an skb. TCP marks such skbs with SKBFL_SHARED_FRAG after skb_splice_from_iter(), so later paths that may modify packet data can first make a private copy. The IPv4/IPv6 datagram append paths did not set this flag when splicing pages into UDP skbs.
That leaves an ESP-in-UDP packet made from shared pipe pages looking like an ordinary uncloned nonlinear skb. ESP input then takes the no-COW fast path for uncloned skbs without a frag_list and decrypts in place over data that is not owned privately by the skb.
Mark IPv4/IPv6 datagram splice frags with SKBFL_SHARED_FRAG, matching TCP. Also make ESP input fall back to skb_cow_data() when the flag is present, so ESP does not decrypt externally backed frags in place.
Private nonlinear skb frags still use the existing fast path.
This intentionally does not change ESP output. In esp_output_head(), the path that appends the ESP trailer to existing skb tailroom without calling skb_cow_data() is not reachable for nonlinear skbs:
skb_tailroom() returns zero when skb->data_len is nonzero, while ESP tailen is positive. Thus ESP output will either use the separate destination-frag path or fall back to skb_cow_data().

Tenable has extracted the preceding description block directly from the Alibaba Cloud Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Update the affected packages.

Plugin Details

Severity: High

ID: 314422

File Name: alinux3_hotfix_sa_2026-0001.nasl

Version: 1.1

Type: Local

Family: Alibaba Cloud Linux Local Security Checks

Published: 5/13/2026

Updated: 5/13/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Critical

Score: 10.0

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5.9

Vector: CVSS2#AV:L/AC:L/Au:S/C:C/I:C/A:C

CVSS Score Source: CVE-2026-43284

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 7.5

Vector: CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:H/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:kernel-hotfix-27289074-5.10.134-19.2, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:kernel-hotfix-27289074-5.10.134-17.1, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:kernel-hotfix-27289074-5.10.134-16.4, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:kernel-hotfix-27289074-5.10.134-14, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:kernel-hotfix-27289074-5.10.134-19.3, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:kernel-hotfix-27289074-5.10.134-17.3, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:kernel-hotfix-27289074-5.10.134-16.5, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:kernel-hotfix-27289074-5.10.134-16, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:kernel-hotfix-27289074-5.10.134-15.1, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:kernel-hotfix-27289074-5.10.134-13, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:kernel-hotfix-27289074-5.10.134-15, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:kernel-hotfix-27289074-5.10.134-15.2, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:kernel-hotfix-27289074-5.10.134-12.3, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:kernel-hotfix-27289074-5.10.134-18.1, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:kernel-hotfix-27289074-5.10.134-12.1, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:kernel-hotfix-27289074-5.10.134-16.3, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:kernel-hotfix-27289074-5.10.134-16.1, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:kernel-hotfix-27289074-5.10.134-13.1, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:kernel-hotfix-27289074-5.10.134-19.1, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:kernel-hotfix-27289074-5.10.134-13.2, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:kernel-hotfix-27289074-5.10.134-12, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:kernel-hotfix-27289074-5.10.134-17, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:kernel-hotfix-27289074-5.10.134-16.2, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:kernel-hotfix-27289074-5.10.134-14.1, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:kernel-hotfix-27289074-5.10.134-19.3.1, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:kernel-hotfix-27289074-5.10.134-19, cpe:/o:alibabacloud:alibaba_cloud_linux_3, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:kernel-hotfix-27289074-5.10.134-17.2, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:kernel-hotfix-27289074-5.10.134-18, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:kernel-hotfix-27289074-5.10.134-12.2

Required KB Items: Host/local_checks_enabled, Host/cpu, Host/Alibaba/release, Host/Alibaba/rpm-list

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 5/10/2026

Vulnerability Publication Date: 5/8/2026

Reference Information

CVE: CVE-2026-43284

Detections

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