markdown-it: Quadratic-time denial of service in inline HTML parsing with html enabled
CVSS score
3.7
EPSS probability
—
Risk score
0.4
Published
15 h ago
Resmî kaynaklarda yeterli kanıt bulunamadı. Bu sonuç “yama yok” anlamına gelmez.
Impact on My Inventory
Only the personal products you have added to your account are assessed; an organisation's inventory does not appear here.
Checking session…
Vulnerability description
CVE AI research
DayBreach AI Explanation
Verified against sourcesSources read
1
Source agreement
Tam uyum
Evidence confidence
%55
Short explanation
markdown-it is vulnerable to a quadratic-time denial of service during inline HTML parsing when the html option or commonmark preset is enabled.
Attackers can submit specially crafted Markdown inputs that block the browser main thread or event loop, leading to a denial of service.
What should be done?
- upgrade markdown-it to version 14.3.3 or 15.0.3
- review inline HTML parsing options
Chain of evidence and sources
markdown-it, HTML seçeneği veya commonmark ön ayarı etkin olduğunda ikinci dereceden hizmet engelleme zafiyetine açıktır.
Bu zafiyet 14.3.3 ve 15.0.3 versiyonlarında giderilmiştir.
Show the technical text from the sources
markdown-it is a Markdown parser. Prior to 14.3.3 and 15.0.3, when the html option or commonmark preset is enabled and the constructs occur inside a paragraph, attacker-controlled Markdown containing repeated unterminated inline HTML comments, processing instructions, declarations, or CDATA sections reaches src/rules_inline/html_inline.ts. Its HTML_TAG_RE match searches the remaining suffix for the appropriate terminator; when no terminator is present, parsing advances to the next opener and repeats the match over overlapping input, causing quadratic processing and denial of service through event-loop blocking or an unresponsive browser main thread. HTML blocks and the default HTML-disabled configuration are not affected by these payloads. This issue is fixed in versions 14.3.3 and 15.0.3.
CVSS vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
CWE: CWE-400, CWE-407
Explanation produced with the local gemini-flash-lite-latest model. Numerical metrics and the KEV, patch and exploit statuses are not determined by AI.
IMPACT: Affected Products and Software
Affected Products
The following products are affected by CVE-2026-111766 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.
| ID | VENDOR | PRODUCT | ACTION |
|---|---|---|---|
| 1 | markdown-it | markdown-it | View |
RED HAT CSAF/VEX: Product Impact Check
SCORING: CVSS from Multiple Sources
CVSS Scores
The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.
| SCORE | VERSION | SEVERITY | VECTOR | SOURCE |
|---|---|---|---|---|
| 3.7 | CVSS V3_1 | LOW | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L | CVE CNA |
| 3.7 | CVSS V31 | LOW | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L | NVD |
Patch and Remediation Guide
Solution & Remediation Advisory
İncelenen resmî kaynaklarda yama durumu doğrulanamadı. Bu sonuç “yama yok” anlamına gelmez.
Public exploit and active exploitation status
Verified exploit intelligence
No verified public PoC, exploit repository or Metasploit module has been found for this CVE yet.
Weakness Classification and Attack Patterns (CWE & CAPEC)
CWE - Common Weakness Enumeration
While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-111766 is associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-111766 weaknesses.
Attack Vector and Accessibility
Official Sources and Advisories
CVSS Vector Radar Chart
3.7 / 10Vulnerability Scoring Details
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:LYama durumu bilinmiyor
Weakness Type (CWE & CAPEC)
Similar Vulnerabilities
Get this vulnerability through the API
Affected products, version ranges, exploitation status and patch information in a single request, with a free key.
curl -H "x-api-key: $DAYBREACH_API_KEY" \ "https://api.daybreach.dev/api/v1/intel/cves/CVE-2026-111766"