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.
Published: 2026-09-07
Score: 6.9 Medium
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Analysis and contextual insights are available on OpenCVE Cloud.

Remediation

No vendor fix or workaround currently provided.

Additional remediation guidance may be available on OpenCVE Cloud.

Tracking

Sign in to view the affected projects.

Advisories

No advisories yet.

History

Mon, 07 Sep 2026 13:00:00 +0000

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'}

Subscriptions

Thephpleague Commonmark
cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-09-07T12:53:51.897Z

Reserved: 2026-09-07T12:34:31.457Z

Link: CVE-2026-86432

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-07T13:20:42.600

Modified: 2026-09-07T13:20:42.600

Link: CVE-2026-86432

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-07T15:15:17Z

Weaknesses