Description
League CommonMark from 1.3.0 before 2.10.2 contains a cross-site scripting vulnerability that allows users posting Markdown to bypass the DisallowedRawHtml extension by ending raw HTML with a bare disallowed tag name. Attackers can place a lone <script or <iframe line followed by a block supplying attributes like src or onload, executing stored scripts in viewers' browsers under default GFM settings.
Published: 2026-10-08
Score: 5.3 Medium
EPSS: n/a
KEV: No
AI Analysis

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Remediation

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Tracking

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Advisories

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History

Thu, 08 Oct 2026 14:15:00 +0000

Type Values Removed Values Added
Description League CommonMark from 1.3.0 before 2.10.2 contains a cross-site scripting vulnerability that allows users posting Markdown to bypass the DisallowedRawHtml extension by ending raw HTML with a bare disallowed tag name. Attackers can place a lone <script or <iframe line followed by a block supplying attributes like src or onload, executing stored scripts in viewers' browsers under default GFM settings.
Title League CommonMark 1.3.0 before 2.10.2 Stored XSS via DisallowedRawHtml Bypass
First Time appeared Thephpleague
Thephpleague commonmark
Weaknesses CWE-80
CPEs cpe:2.3:a:thephpleague:commonmark:-:*:*:*:*:*:*:*
Vendors & Products Thephpleague
Thephpleague commonmark
References
Metrics cvssV3_1

{'score': 6.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'}

cvssV4_0

{'score': 5.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N'}

Subscriptions

Thephpleague Commonmark
cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-10-08T14:10:30.523Z

Reserved: 2026-10-05T21:59:09.591Z

Link: CVE-2026-105829

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses
  • CWE-80

    Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)