python-markdown2 through 2.5.5 contains a denial of service vulnerability that allows remote users to exhaust CPU by submitting Markdown with unclosed inline link destinations. Attackers can submit repeated '[a](' or '![a](' sequences, causing _find_balanced to rescan the remaining document for each link and consume quadratic CPU time.

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Fixes

Solution

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Workaround

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History

Wed, 28 Oct 2026 21:30:00 +0000

Type Values Removed Values Added
Description python-markdown2 through 2.5.5 contains a denial of service vulnerability that allows remote users to exhaust CPU by submitting Markdown with unclosed inline link destinations. Attackers can submit repeated '[a](' or '![a](' sequences, causing _find_balanced to rescan the remaining document for each link and consume quadratic CPU time.
Title python-markdown2 through 2.5.5 Denial of Service via Unclosed Inline Link Destinations
First Time appeared Python-markdown2 Project
Python-markdown2 Project python-markdown2
Weaknesses CWE-407
CPEs cpe:2.3:a:python-markdown2_project:python-markdown2:*:*:*:*:*:*:*:*
Vendors & Products Python-markdown2 Project
Python-markdown2 Project python-markdown2
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 8.7, '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'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-10-28T21:11:20.814Z

Reserved: 2026-10-28T17:31:29.498Z

Link: CVE-2026-118694

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-28T22:17:13.700

Modified: 2026-10-28T22:17:13.700

Link: CVE-2026-118694

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-29T05:45:14Z

Weaknesses