Detections
Analytics
Amazon Linux 2023 : python3-mistune (ALAS2023-2026-3386)
high Nessus Plugin ID 377958
Synopsis
The remote Amazon Linux 2023 host is missing a security update.Description
It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2023-2026-3386 advisory.Mistune before 3.3.0 contains an inefficient algorithmic complexity vulnerability in parse_link_text that allows remote attackers to cause denial of service through unbalanced square brackets. Attackers can submit markdown containing long runs of unmatched brackets to mistune.html(), triggering repeated forward scans that stall worker processes for minutes. (CVE-2026-115347)
Mistune before 3.3.0 contains an algorithmic complexity vulnerability in the inline link parser that allows unauthenticated attackers to exhaust CPU by submitting long runs of unmatched '[' characters.
Attackers can send small markdown payloads that trigger O(N^2) parse_link_text and parse_link_label probing, occupying rendering workers for 30+ seconds per 16 KB input. (CVE-2026-115352)
Tenable has extracted the preceding description block directly from the tested product security advisory.
Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.
Solution
Run 'dnf update python-mistune --releasever 2023.12.20261109' or or 'dnf update --advisory ALAS2023-2026-3386 --releasever 2023.12.20261109' to update your system.See Also
https://alas.aws.amazon.com//AL2023/ALAS2023-2026-3386.html
https://alas.aws.amazon.com/faqs.html
Plugin Details
Severity: High
ID: 377958
File Name: al2023_ALAS2023-2026-3386.nasl
Version: 1.1
Type: Local
Agent: unix
Published: 11/9/2026
Updated: 11/9/2026
Supported Sensors: Nessus Agent, Continuous Assessment, Nessus
Risk Information
VPR
Risk Factor: Low
Score: 3
Percentile: 23.82
CVSS v2
Risk Factor: High
Base Score: 7.8
Temporal Score: 5.8
Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C
CVSS Score Source: CVE-2026-115352
CVSS v3
Risk Factor: High
Base Score: 7.5
Temporal Score: 6.5
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C
CVSS v4
Risk Factor: High
Base Score: 8.7
Threat Score: 6.6
Threat Vector: CVSS:4.0/E:U
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Vulnerability Information
CPE: cpe:/o:amazon:linux:2023, p-cpe:/a:amazon:linux:python-mistune-debugsource, p-cpe:/a:amazon:linux:python3-mistune-debuginfo, p-cpe:/a:amazon:linux:python3-mistune
Required KB Items: Host/local_checks_enabled, Host/AmazonLinux/release, Host/AmazonLinux/rpm-list
Exploit Ease: No known exploits are available
Patch Publication Date: 11/9/2026
Vulnerability Publication Date: 10/22/2026