Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1359 CNY

100%
Buy Us a Coffee

CVE-2026-86430— league/commonmark before 2.9.1 Denial of Service via parsing

Quick assessment

Affected
thephpleague commonmark
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

The League of Extraordinary Packages league/commonmark是The League of Extraordinary Packages组织开源的一款Markdown解析组件。 The League of Extraordinary Packages league/commonmark 2.9.1之前版本存在资源管理错误漏洞，该漏洞源于围栏代码块检测、参考链接标签查找和强调分隔符处理在特制输入上执行超线性工作，可能导致攻击者提交带有长反引号序列、嵌套括号或分隔

CVSS 7.5 · High EPSS 0.49% · P41

Affected Version Matrix 2

VendorProduct Version RangeStatus
thephpleague commonmark 0.6.0< 2.9.1 affected
2.9.1 unaffected
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-86430

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
league/commonmark before 2.9.1 Denial of Service via parsing
Source: CVE Program / CVE List V5
Vulnerability Description
league/commonmark versions before 2.9.1 contain multiple denial of service vulnerabilities in fenced code block detection, reference link label lookup, and emphasis delimiter processing that perform super-linear work on crafted input. Attackers can submit specially crafted Markdown with long backtick runs, nested brackets, or delimiter sequences to consume disproportionate CPU time and prevent legitimate requests from completing.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Source: CVE Program / CVE List V5
Vulnerability Type
算法复杂性
Source: CVE Program / CVE List V5
Vulnerability Title
The League of Extraordinary Packages league/commonmark 资源管理错误漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
The League of Extraordinary Packages league/commonmark是The League of Extraordinary Packages组织开源的一款Markdown解析组件。 The League of Extraordinary Packages league/commonmark 2.9.1之前版本存在资源管理错误漏洞，该漏洞源于围栏代码块检测、参考链接标签查找和强调分隔符处理在特制输入上执行超线性工作，可能导致攻击者提交带有长反引号序列、嵌套括号或分隔
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
thephpleague commonmark 0.6.0 ~ 2.9.1 -

II. Public POCs for CVE-2026-86430

# POC Description Source Link Shenlong Link
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-86430

请登录查看更多情报信息。

Vendor Advisories for CVE-2026-86430 (2)

Same Patch Batch · thephpleague · 2026-09-07 · 8 CVEs total

CVE-2026-86429 7.5 HIGH commonmark before 2.9.1 Denial of Service via SmartPunct and Attributes
CVE-2026-86435 7.5 HIGH commonmark 1.5.0 before 2.8.4 Denial of Service via Footnote
CVE-2026-86434 7.5 HIGH commonmark 2.0.0 through 2.8.3 Denial of Service via Slug Collision
CVE-2026-86433 7.5 HIGH commonmark 1.5.0 before 2.8.4 Denial of Service via Attributes
CVE-2026-86428 7.5 HIGH commonmark 1.5.0 before 2.10.0 Denial of Service via Attributes
CVE-2026-86431 7.2 HIGH commonmark before 2.9.1 XSS via AttributesExtension form feed bypass
CVE-2026-86432 5.3 MEDIUM commonmark 2.0.0 before 2.8.4 Denial of Service via XML

IV. Related Vulnerabilities

Same product: commonmark
Same vendor: thephpleague
Same weakness: CWE-407

V. Comments for CVE-2026-86430

No comments yet

Leave a comment