Home/CVE/Cross-site scripting (XSS) vulnerability in the PHP League CommonMark library versions 0.15.6 through 0.18.x before 0.18
CVE

CVE-2018-20583

Cross-site scripting (XSS) vulnerability in the PHP League CommonMark library versions 0.15.6 through 0.18.x before 0.18

Cross-site scripting (XSS) vulnerability in the PHP League CommonMark library versions 0.15.6 through 0.18.x before 0.18.1 allows remote attackers to insert unsafe URLs into HTML (even if allow_unsafe_links is false) via a newline character (e.g., writing javascript as javascri%0apt).

MEDIUM · CVSS 6.1 EPSS 0.0031
Schedule remediation
  • Public exploit or PoC is available
Sigma rules0 YARA rules0
⬡

Weakness Classification

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
▤

Affected Products & Versions

1
thephpleague commonmark>= 0.15.6 and <= 0.18.0
▤

Affected Packages

1
Language-ecosystem packages (from OSV) tied to this CVE, with the version that fixes it - the dependency-level detail NVD doesn’t carry.
Packagist league/commonmark MEDIUM fixed in 0.18.1
⚠

Public Exploits & PoCs

1
pocgithub.com · issues/337github.com
▣

Scoring & Timeline

6.1
MEDIUM · CVSS v3.0 · cve@mitre.org
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD30 Dec 2018 · 05:29 AM
CVSS VectorCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
🔗

References & Sources

2
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://commonmark.thephpleague.com/changelog/Release NotesThird Party Advisory
https://github.com/thephpleague/commonmark/releases/tag/0.18.1Release NotesThird Party Advisory
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