CVE-2026-105829

League CommonMark 1.3.0 before 2.10.2 Stored XSS via DisallowedRawHtml Bypass

Published Oct 8, 2026 CVSS 4.0 · 5.3 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

Sign in to view the affected projects.

Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Oct 10, 2026, 3:05 AM
Reserved
Oct 5, 2026, 9:59 PM
Status
Awaiting Analysis
Published
Oct 8, 2026, 3:17 PM
Modified
Oct 10, 2026, 4:18 AM