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
CVE-2026-105829
Score 6.1 from GitHub Security Advisory published 2026-10-08. A secondary CVSS source baseline 6.1; sources differ by 0.0.
- Lower severity and no public exploit yet
A fix is available — apply it.
- CVSS v3
- 6.1
- EG Score
- 6.1MEDIUMhigh confidence
- EG Risk
- 32EG Risk 32/100CISA SSVC
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity61% × 45%Exploitation0% × 40%Automatability30% × 15%CISA SSVC: Track at low or medium mission impact; Track or Attend at high (mission-essential systems).Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high. - EPSS PROB
- 0.2%
- EPSS %ILE
- 9th
- KEV
- Not listed
CISA SSVCTrack at low or medium mission impact; Track or Attend at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
Exploitation none (no KEV listing, exploit record or EPSS ≥ 50%) · Automatable unknown (not published for this CVE) · Technical impact partial (CVSS below 9.0). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table
Published
October 8, 2026
Last Modified
October 8, 2026
Advisory Details (2)
Auto-updated Oct 8, 2026League CommonMark 1.3.0 before 2.10.2 Stored XSS via DisallowedRawHtml Bypass | Advisories | VulnCheck
https://www.vulncheck.com/advisories/league-commonmark-1.3.0-before-2.10.2-stored-xss-via-disallowedrawhtml-bypassDisallowedRawHtml bypassed when a disallowed tag name ends the raw-HTML literal: `<script` alone survives the shipped GFM defaults, giving stored XSS to anyone who can post Markdown · Advisory · thephpleague/commonmark · GitHub
Affected: 2.8.1. That fix widened the character class but still requires one character, so
https://github.com/thephpleague/commonmark/security/advisories/GHSA-97jj-33gv-5xf9Vendor Advisories for CVE-2026-105829(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Affected Packages
(1 across 1 ecosystem)
Packagist(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| league/commonmark | 1.3.0 ... 2.9.2 (79 versions) |
| — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 11× in last 7d / 11× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-10-09 23:12 UTCEG score recompute
- 2026-10-09 23:12 UTCGHSA enrichment
- 2026-10-09 20:06 UTCEPSS rescore
- 2026-10-08 21:38 UTCGHSA enrichment
- 2026-10-08 16:25 UTCEG score recompute
- 2026-10-08 16:25 UTCGHSA enrichment
- 2026-10-08 15:37 UTCEG score recompute
- 2026-10-08 15:37 UTCGHSA enrichment
- 2026-10-08 15:20 UTCEG score recompute
- 2026-10-08 14:18 UTCEG score recompute
- 2026-10-08 14:16 UTCMITRE cvelistV5first tracked
Related CVEs(same product + same CWE)
Same product
10 shownPackagist:league/commonmark
Frequently asked(5)
What is CVE-2026-105829?
When was CVE-2026-105829 disclosed?
Is CVE-2026-105829 actively exploited?
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How do I remediate CVE-2026-105829?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-105829
Is Your Infrastructure Affected by CVE-2026-105829?
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