Alibaba Cloud Linux 3 : 0305: perl (ALINUX3-SA-2026:0305)

critical Nessus Plugin ID 367781

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-SA-2026:0305 advisory.

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

CVE-2026-13221:
Perl versions through 5.43.9 produce silently incorrect regular expression matches when an alternation of more than 65535 fixed string branches is compiled into a trie in Perl_study_chunk.
When such branches are combined into a trie, the delta between the first branch and the shared tail is stored in a 16-bit field. A branch count above 65535 overflows the field, and the trie's match decision table is truncated with no warning or error.
A pattern of this shape produces false positive matches (matching strings it should not) and false negative matches (failing to match strings it should). When such a pattern gates an access or filtering decision, the result is wrong.

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: Critical

ID: 367781

File Name: alinux3_sa_2026-0305.nasl

Version: 1.1

Type: Local

Family: Alibaba Cloud Linux Local Security Checks

Published: 10/20/2026

Updated: 10/20/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.3

Percentile: 96.31

CVSS v2

Risk Factor: High

Base Score: 9.4

Temporal Score: 7

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

CVSS Score Source: CVE-2026-13221

CVSS v3

Risk Factor: Critical

Base Score: 9.1

Temporal Score: 7.9

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

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

Vulnerability Information

CPE: cpe:/o:alibabacloud:alibaba_cloud_linux_3, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:perl-attribute-handlers, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:perl-devel-peek, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:perl-devel-selfstubber, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:perl-devel, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:perl-errno, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:perl-extutils-embed, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:perl-extutils-miniperl, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:perl-interpreter, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:perl-io-zlib, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:perl-io, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:perl-libnetcfg, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:perl-libs, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:perl-locale-maketext-simple, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:perl-macros, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:perl-math-complex, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:perl-memoize, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:perl-module-loaded, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:perl-net-ping, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:perl-open, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:perl-pod-html, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:perl-selfloader, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:perl-test, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:perl-tests, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:perl-time-piece, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:perl-utils, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:perl

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

Exploit Ease: No known exploits are available

Patch Publication Date: 10/19/2026

Vulnerability Publication Date: 7/13/2026

Reference Information

CVE: CVE-2026-13221

Detections

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