CVE - CVE-2025-46734

CVE-ID
CVE-2025-46734	Learn more at National Vulnerability Database (NVD) • CVSS Severity Rating • Fix Information • Vulnerable Software Versions • SCAP Mappings • CPE Information
Description
league/commonmark is a PHP Markdown parser. A cross-site scripting (XSS) vulnerability in the Attributes extension of the league/commonmark library (versions 1.5.0 through 2.6.x) allows remote attackers to insert malicious JavaScript calls into HTML. The league/commonmark library provides configuration options such as `html_input: 'strip'` and `allow_unsafe_links: false` to mitigate cross-site scripting (XSS) attacks by stripping raw HTML and disallowing unsafe links. However, when the Attributes Extension is enabled, it introduces a way for users to inject arbitrary HTML attributes into elements via Markdown syntax using curly braces. Version 2.7.0 contains three changes to prevent this XSS attack vector: All attributes starting with `on` are considered unsafe and blocked by default; support for an explicit allowlist of allowed HTML attributes; and manually-added `href` and `src` attributes now respect the existing `allow_unsafe_links` configuration option. If upgrading is not feasible, please consider disabling the `AttributesExtension` for untrusted users and/or filtering the rendered HTML through a library like HTMLPurifier.
References
Note: References are provided for the convenience of the reader to help distinguish between vulnerabilities. The list is not intended to be complete.
MISC:https://github.com/thephpleague/commonmark/commit/f0d626cf05ad3e99e6db26ebcb9091b6cd1cd89b URL:https://github.com/thephpleague/commonmark/commit/f0d626cf05ad3e99e6db26ebcb9091b6cd1cd89b MISC:https://github.com/thephpleague/commonmark/security/advisories/GHSA-3527-qv2q-pfvx URL:https://github.com/thephpleague/commonmark/security/advisories/GHSA-3527-qv2q-pfvx
Assigning CNA
GitHub (maintainer security advisories)
Date Record Created
20250428	Disclaimer: The record creation date may reflect when the CVE ID was allocated or reserved, and does not necessarily indicate when this vulnerability was discovered, shared with the affected vendor, publicly disclosed, or updated in CVE.
Phase (Legacy)
Assigned (20250428)
Votes (Legacy)

Comments (Legacy)

Proposed (Legacy)
N/A
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