Skip to content

PHP League CommonMark vulnerable to Cross-Site Scripting (XSS)

Moderate severity GitHub Reviewed Published May 14, 2022 to the GitHub Advisory Database • Updated Feb 6, 2024

Package

composer league/commonmark (Composer)

Affected versions

>= 0.15.6, < 0.18.1

Patched versions

0.18.1

Description

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).

References

Published by the National Vulnerability Database Dec 30, 2018
Published to the GitHub Advisory Database May 14, 2022
Reviewed Sep 12, 2022
Last updated Feb 6, 2024

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

EPSS score

0.340%
(71st percentile)

Weaknesses

CVE ID

CVE-2018-20583

GHSA ID

GHSA-qx76-c53f-5c7q

Source code

Credits

Loading Checking history
See something to contribute? Suggest improvements for this vulnerability.