Cross-site Scripting (XSS) Affecting php-league-commonmark package, versions <2.3.9-1+deb12u1
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-ECHOLATEST-PHPLEAGUECOMMONMARK-18612362
- published11 Aug 2026
- disclosed5 May 2025
Introduced: 5 May 2025
CVE-2025-46734 (opens in a new tab)How to fix?
Upgrade Echo:latest php-league-commonmark to version 2.3.9-1+deb12u1 or higher.
NVD Description
Note: Versions mentioned in the description apply only to the upstream php-league-commonmark package and not the php-league-commonmark package as distributed by Echo.
See How to fix? for Echo:latest relevant fixed versions and status.
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.