CVE-2026-48591

Summary

Improper Neutralization of Script in Attributes in a Web Page vulnerability in pragdave earmark allows stored cross-site scripting via unescaped HTML attribute values.

'Elixir.Earmark.Transform':_make_att1/2 in lib/earmark/transform.ex splices attribute values verbatim between two literal " bytes: [" ", name, "=&#34;", value, "&#34;"]. Text nodes are routed through the existing escape function which encodes " as &quot;, but attribute values never visit that path. A markdown link whose URL or title contains a bare " closes the attribute early and lets the trailing bytes be parsed by the browser as fresh HTML attributes. For example, [click](http://example.com/?a=x&#34; onerror="alert(1)) renders as <a href="http://example.com/?a=x" onerror="alert(1)">click</a>, executing arbitrary JavaScript in the victim's browser.

The earmark library is no longer maintained and has been retired on Hex. No patched version will be released. All releases from 1.4.1 onward are affected, and users should migrate to a maintained Markdown library such as MDEx.

This issue affects earmark from 1.4.1 onward.

Affected Software

VendorProductVersion RangeStatus
pragdaveearmark1.4.1 < *affected
pragdaveearmark8236a0570bd894b50e360da08131ec3294c20799 < *affected

Weaknesses

  • CWE-83: CWE-83 Improper Neutralization of Script in Attributes in a Web Page

Workarounds

Migrate to a maintained Markdown library such as MDEx (https://hex.pm/packages/mdex). The earmark package has been retired on Hex and no patched release will be made.

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References