CVE-2026-86432

commonmark 2.0.0 before 2.8.4 Denial of Service via XML

Published Sep 7, 2026 CVSS 4.0 · 6.9 Medium EPSS < 1% KEV · Not listed
Description
commonmark versions from 2.0.0 before 2.8.4 contain a denial of service vulnerability in XmlRenderer that emits depth-proportional indentation for every XML tag. Attackers can provide deeply nested Markdown or AST structures to cause quadratic memory consumption and output amplification, exhausting server resources.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

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

Type Values Removed Values Added
Description commonmark versions from 2.0.0 before 2.8.4 contain a denial of service vulnerability in XmlRenderer that emits depth-proportional indentation for every XML tag. Attackers can provide deeply nested Markdown or AST structures to cause quadratic memory consumption and output amplification, exhausting server resources.
Title commonmark 2.0.0 before 2.8.4 Denial of Service via XML
First Time appeared Thephpleague
Thephpleague commonmark
Weaknesses CWE-405
CPEs cpe:2.3:a:thephpleague:commonmark:*:*:*:*:*:*:*:*
Vendors & Products Thephpleague
Thephpleague commonmark
References
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'}

cvssV4_0

{'score': 6.9, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Oct 8, 2026, 3:25 PM
Reserved
Sep 7, 2026, 12:34 PM
Status
Awaiting Analysis
Published
Sep 7, 2026, 1:20 PM
Modified
Oct 8, 2026, 4:17 PM