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.
Published: 2026-10-28
Score: 8.7 High
EPSS: < 1% Very Low
KEV: No
AI Analysis

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Remediation

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Tracking

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Advisories

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History

Fri, 30 Oct 2026 12:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-606
References
Metrics threat_severity

None

threat_severity

Important


Thu, 29 Oct 2026 18:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


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'}


Subscriptions

Python-markdown2 Project Python-markdown2
cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-10-29T17:22:18.429Z

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

Link: CVE-2026-118694

cve-icon Vulnrichment

Updated: 2026-10-29T15:43:39.290Z

cve-icon NVD

Status : Deferred

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

Modified: 2026-10-29T18:17:28.427

Link: CVE-2026-118694

cve-icon Redhat

Severity : Important

Publid Date: 2026-10-28T21:11:20Z

Links: CVE-2026-118694 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-10-30T14:15:08Z

Weaknesses