NIXPKGS-2026-1736

GitHub issue published on

Permalink CVE-2026-44899

4.7 MEDIUM

CVSS version (CVSS): 3.1
Attack Vector (AV): Network (N)
Attack Complexity (AC): Low (L)
Privileges Required (PR): None (N)
User Interaction (UI): Required (R)
Scope (S): Changed (C)
Confidentiality (C): Low (L)
Integrity (I): None (N)
Availability (A): None (N)
Modified Attack Vector (MAV): Network (N)
Modified Attack Complexity (MAC): Low (L)
Modified Privileges Required (MPR): None (N)
Modified User Interaction (MUI): Required (R)
Modified Confidentiality (MC): Low (L)
Modified Scope (MS): Changed (C)
Modified Integrity (MI): None (N)
Modified Availability (MA): None (N)

updated an hour ago by @LeSuisse Activity log

Created suggestion 8 hours ago
@LeSuisse accepted an hour ago
@LeSuisse published on GitHub an hour ago

Mistune Image Directive CSS Injection Vulnerability

Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.2.1, the Image directive plugin validates the :width: and :height: options with a regex compiled as _num_re = re.compile(r"^\d+(?:\.\d*)?"). When the validated value is not a plain integer, render_block_image() inserts it directly into a style="width:...;" or style="height:...;" attribute. Because the value was accepted by the prefix-only regex, any CSS after the leading digits reaches the style= attribute verbatim and without escaping. This vulnerability is fixed in 3.2.1.